| Part 1 Basic Structural Principles |
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1 | (126) |
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3 | (10) |
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Proteins are polypeptide chains |
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4 | (1) |
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The genetic code specifies 20 different amino acid side chains |
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4 | (1) |
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Cysteines can form disulfide bridges |
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5 | (3) |
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Peptide units are building blocks of protein structures |
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8 | (1) |
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Glycine residues can adopt many different conformations |
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9 | (1) |
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Certain side-chain conformations are energetically favorable |
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10 | (1) |
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Many proteins contain intrinsic metal atoms |
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11 | (1) |
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12 | (1) |
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12 | (1) |
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2. Motifs of Protein Structure |
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13 | (22) |
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The interior of proteins is hydrophobic |
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14 | (1) |
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The alpha (Alpha) helix is an important element of secondary structure |
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14 | (2) |
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The Alpha helix has a dipole moment |
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16 | (1) |
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Some amino acids are preferred in Alpha helices |
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16 | (3) |
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Beta (Beta) sheets usually have their Beta strands either parallel of antiparallel |
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19 | (2) |
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Loop regions are at the surface of protein molecules |
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21 | (1) |
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Schematic pictures of proteins highlight secondary structure |
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22 | (1) |
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Topology diagrams are useful for classification of protein structures |
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23 | (1) |
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Secondary structure elements are connected to form simple motifs |
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24 | (2) |
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The hairpin Beta motif occurs frequently in protein structures |
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26 | (1) |
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The Greek key motif is found in antiparallel Beta sheets |
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27 | (1) |
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The Beta-Alpha-Beta motif contains two parallel Beta strands |
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27 | (1) |
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Protein molecules are organized in a structural hierarchy |
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28 | (1) |
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Large polypeptide chains fold into several domains |
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29 | (1) |
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Domains are built from structural motifs |
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30 | (1) |
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Simple motifs combine to form complex motifs |
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30 | (1) |
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Protein structures can be divided into three main classes |
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31 | (1) |
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32 | (1) |
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33 | (2) |
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3. Alpha-Domain Structures |
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35 | (12) |
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Coiled-coil Alpha helices contain a repetitive heptad amino acid sequence pattern |
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35 | (2) |
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The four-helix bundle is a common domain structure in Alpha proteins |
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37 | (2) |
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Alpha-helical domains are sometimes large and complex |
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39 | (1) |
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The globin fold is present in myoglobin and hemoglobin |
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40 | (1) |
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Geometric considerations determine Alpha-helix packing |
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40 | (1) |
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Ridges of one Alpha helix fit into grooves of an adjacent helix |
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40 | (1) |
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The globin fold has been preserved during evolution |
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41 | (1) |
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The hydrophobic interior is preserved |
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42 | (1) |
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Helix movements accommodate interior side-chain mutations |
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43 | (1) |
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Sickle-cell hemoglobin confers resistance to malaria |
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43 | (2) |
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45 | (1) |
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45 | (2) |
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47 | (20) |
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Parallel Beta strands are arranged in barrels or sheets |
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47 | (1) |
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Alpha/beta barrels occur in many different enzymes |
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48 | (1) |
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Branched hydrophobic side chains dominate the core of Alpha/Beta barrels |
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49 | (2) |
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Pyruvate kinase contains several domains, one of which is an Alpha/Beta barrel |
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51 | (1) |
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Double barrels have occurred by gene fusion |
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52 | (1) |
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The active site is formed by loops at one end of the Alpha/Beta barrel |
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53 | (1) |
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Alpha/beta barrels provide examples of evolution of new enzyme activities |
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54 | (1) |
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Leucine-rich motifs form an Alpha/Beta-horseshoe fold |
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55 | (1) |
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Alpha/beta twisted open-sheet structures contain Alpha helices on both sides of the Beta sheet |
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56 | (1) |
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Open Beta-sheet structures have a variety of topologies |
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57 | (1) |
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The positions of active sites can be predicted in Alpha/Beta structures |
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57 | (2) |
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Tyrosyl-tRNA synthetase has two different domains (Alpha/Beta+Alpha) |
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59 | (1) |
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Carboxypeptidase is an Alpha/Beta protein with a mixed Beta sheet |
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60 | (2) |
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Arabinose-binding protein has two similar Alpha/Beta domains |
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62 | (1) |
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63 | (1) |
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64 | (3) |
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67 | (22) |
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Up-and-down barrels have a simple topology |
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68 | (1) |
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The retinol-binding protein binds retinol inside an up-and-down Beta barrel |
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68 | (1) |
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Amino acid sequence reflects Beta Structure |
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69 | (1) |
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The retinol-binding protein belongs to a superfamily of protein structures |
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70 | (1) |
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Neuraminidase folds into up-and-town Beta sheets |
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70 | (1) |
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Folding motifs form a propeller-like structure in neuraminidase |
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71 | (1) |
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The active site is in the middle of one side of the propeller |
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72 | (1) |
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Greek key motifs occur frequently in antiparallel Beta structures |
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72 | (2) |
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The Gamma-crystallin molecule has two domains |
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74 | (1) |
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The domain structure has a simple topology |
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74 | (1) |
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Two Greek key motifs form the domain |
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74 | (1) |
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The two domains have identical topology |
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75 | (1) |
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The two domains have similar structures |
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76 | (1) |
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The Greek key motifs in Gamma crystallin are evolutionarily related |
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76 | (1) |
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The Greek key motifs can form jelly roll barrles |
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77 | (1) |
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The jelly roll motif is wrapped around a barrel |
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77 | (1) |
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The jelly roll barrel is usually divided into two sheets |
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78 | (1) |
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The functional hemagglutining subunit has two polypeptide chains |
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79 | (1) |
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The subunit structure is divided into a stem and a tip |
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79 | (1) |
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The receptor binding site is formed by the jelly roll domain |
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80 | (1) |
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Hemaggluthining acts as a membrane fusogen |
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80 | (1) |
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The structure of hemagglutinin is affected by pH changes |
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81 | (3) |
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Parallel Beta-helix domains have a novel fold |
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84 | (1) |
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85 | (2) |
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87 | (2) |
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6. Folding and Flexibility |
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89 | (32) |
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Globular proteins are only marginally stable |
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90 | (1) |
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Kinetic factors are important for folding |
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91 | (1) |
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Molten globules are intermediates in folding |
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92 | (1) |
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Burying hydrophobic side chains is a key event |
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93 | (1) |
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Both single and multiple folding pathways have been observed |
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93 | (3) |
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Enzymes assist formation of proper disulfide bonds during folding |
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96 | (2) |
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Isomerization of proline residues can be a rate-limiting step in protein folding |
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98 | (1) |
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Proteins can fold or unfold inside chaperonins |
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99 | (1) |
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GroEL is a cylindrical structure with a central channel in which newly synthesized polypeptides bind |
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100 | (2) |
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GroES closes off one end of the GroEL cylinder |
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102 | (1) |
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The GroEL-GroES complex binds and releases newly synthesized polypeptides in an ATP-dependent cycle |
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102 | (2) |
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The folded state has a flexible structure |
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104 | (1) |
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Conformational changes in a protein kinase are important for cell cycle regulation |
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105 | (4) |
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Peptide binding to calmodulin induces a large interdomain movement |
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109 | (1) |
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Serpins inhibit serine proteinases with a spring-loaded safety catch mechanism |
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110 | (3) |
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Effector molecules switch allosteric proteins between R and T states |
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113 | (1) |
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X-ray structures explain the allosteric properties of phosphofructokinase |
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114 | (3) |
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117 | (2) |
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119 | (2) |
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121 | (6) |
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The DNA double helix is different in A- and B-DNA |
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121 | (1) |
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The DNA helix has major and minor grooves |
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122 | (1) |
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Z-DNA forms a zigzag pattern |
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123 | (1) |
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B-DNA is the preferred conformation in vivo |
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124 | (1) |
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Specific base sequences can be recognized in B-DNA |
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124 | (1) |
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125 | (1) |
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126 | (1) |
| Part 2 Structure, Function, and Engineering |
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127 | (266) |
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8. DNA Recognition in Procaryotes by Helix-Turn-Helix Motifs |
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129 | (22) |
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A molecular mechanism for gene control |
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129 | (1) |
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Repressor and Cro proteins operate a procaryotic genetic switch region |
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130 | (1) |
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The x-ray structure of the complete lambda Cro protein is known |
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131 | (1) |
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The x-ray structure of the DNA-binding domain of the lambda repressor is known |
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132 | (1) |
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Both lambda Cro and repressor proteins have a specific DNA-binding motif |
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133 | (1) |
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Model building predicts Cro-DNA interactions |
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134 | (1) |
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Genetic studies agree with the structural model |
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135 | (1) |
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The x-ray structure of DNA complexes with 434 Cro and repressor revealed novel features of protein-DNA interactions |
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136 | (1) |
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The structures of 434 Cro and the 434 repressor DNA-binding domain the very similar |
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137 | (1) |
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The proteins impose precise distortions on the B-DNA in the complexes |
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138 | (1) |
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Sequence-specific protein-DNA interactions recognize operator regions |
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138 | (1) |
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Protein-DNA backbone interactions determine DNA conformation |
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139 | (1) |
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Conformational changes of DNA are important for differential binding of repressor and Cro to different operator sites |
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140 | (1) |
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The essence of phage repressor and Cro |
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141 | (1) |
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DNA binding is regulated by allosteric control |
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142 | (1) |
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The trp repressor forms a helix-turn-helix motif |
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142 | (1) |
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A conformational change operates a functional switch |
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142 | (1) |
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Lac repressor binds to both the major and minor grooves inducing a sharp bend in the DNA |
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143 | (3) |
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CAP-induced DNA binding could activate transcription |
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146 | (1) |
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147 | (1) |
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148 | (3) |
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9. DNA Recognition by Eucaryotic Transcription Factors |
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151 | (24) |
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Transcription is activated by protein-protein interactions |
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152 | (1) |
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The TATA box-binding protein is ubiquitous |
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153 | (1) |
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The three-dimensional structures of TBP-TATA box complexes are known |
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154 | (1) |
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A Beta sheet in TBP forms the DNA-binding site |
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154 | (1) |
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TBP binds in the minor groove and induces large structural changes in DNA |
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155 | (2) |
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The interaction area between TBP and the TATA box is mainly hydrophobic |
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157 | (1) |
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Functional implications of the distortion of DNA by TBP |
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158 | (1) |
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TFIIA and TFIIB bind to both TBP and DNA |
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159 | (1) |
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Homeodomain proteins are involved in the development of many eucaryotic organisms |
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159 | (1) |
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Monomers of homeodomain proteins bind to DNA through a helix-turn-helix motif |
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160 | (2) |
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In vivo specificity of homeodomain transcription factors depends on interactions with other proteins |
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162 | (2) |
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POU regions bind to DNA by two tandemly oriented helix-turn-helix motifs |
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164 | (2) |
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Much remains to be learnt about the function of homeodomains in vivo |
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166 | (1) |
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Understanding tumorigenic mutations |
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166 | (1) |
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The monomeric p53 polypeptide chain is divided in three domains |
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167 | (1) |
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The oligomerization domain forms tetramers |
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167 | (1) |
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The DNA-binding domain of p53 is an antiparallel Beta barrel |
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168 | (1) |
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Two loop regions and one Alpha helix of p53 bind to DNA |
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169 | (1) |
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Tumorigenic mutations occur mainly in three regions involved in DNA binding |
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170 | (2) |
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172 | (1) |
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172 | (3) |
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10. Specific Transcription Factors Belong to a Few Families |
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175 | (30) |
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Several different groups of zinc-containing motifs have been observed |
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176 | (1) |
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The classic zinc fingers bind to DNA in tandem along the major groove |
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177 | (1) |
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The finger region of the classic zinc finger motif interacts with DNA |
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178 | (3) |
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Two zinc-containing motifs in the glucocorticoid receptor form one DNA-binding domain |
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181 | (2) |
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A dimer of the glucocorticoid receptor binds to DNA |
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183 | (1) |
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An Alpha helix in the first zinc motif provides the specific protein-DNA interactions |
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184 | (1) |
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Three residues in the recognition helix provide the sequence-specific interactions with DNA |
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184 | (1) |
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The retinoid X receptor forms heterodimers that recognize tandem repeats with variable spacings |
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185 | (2) |
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Yeast transcription factor GAL4 contains a binuclear zinc cluster in its DNA-binding domain |
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187 | (1) |
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The zinc cluster regions of GAL4 bind at the two ends of the enhancer element |
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188 | (1) |
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The linker region also contributes to DNA binding |
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189 | (1) |
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DNA-binding site specificity among the C(6)-zinc cluster family of transcription factors is achieved by the linker regions |
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190 | (1) |
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Families of zinc-containing transcription factors bind to DNA in several different ways |
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191 | (1) |
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Leucine zippers provide dimerization interactions for some eucaryotic transcription factors |
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191 | (2) |
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The GCN4 basic region leucine zipper binds DNA as a dimer of two uninterrupted Alpha helices |
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193 | (1) |
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GCN4 binds to DNA with both specific and nonspecific contacts |
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194 | (2) |
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The HLH motif is involved in homodimer and heterodimer associations |
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196 | (2) |
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The Alpha-helical basic region of the b/HLH motif binds in the major groove of DNA |
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198 | (1) |
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The b/HLH/zip family of transcription factors have both HLH and leucine zipper dimerization motifs |
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199 | (2) |
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Max and MyoD recognize the DNA HLH consensus sequence by different specific protein-DNA interactions |
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201 | (1) |
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201 | (2) |
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203 | (2) |
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11. An Example of Enzyme Catalysis: Serine Proteinases |
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205 | (18) |
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Proteinases form four functional families |
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205 | (1) |
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The catalytic properties of enzymes are reflected in K(m) and k(cat) values |
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206 | (1) |
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Enzymes decrease the activation energy of chemical reactions |
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206 | (2) |
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Serine proteinases cleave peptide bonds by forming tetrahedral transition states |
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208 | (1) |
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Four important structural features are required for the catalytic action of serine proteinases |
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209 | (1) |
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Convergent evolution has produced two different serine proteinases with similar catalytic mechanisms |
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210 | (1) |
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The chymotrypsin structure has two antiparallel Beta-barrel domains |
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210 | (1) |
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The active site is formed by two loop regions from each domain |
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211 | (1) |
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Did the chymotrypsin molecule evolve by gene duplication? |
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212 | (1) |
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Different side chains in the substrate specificity pocket confer preferential cleavage |
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212 | (1) |
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Engineered mutations in the substrate specificity pocket change the rate of catalysis |
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213 | (2) |
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The Asp 189-Lys mutation in trypsin causes unexpected changes in substrate specificity |
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215 | (1) |
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The structure of the serine proteinase subtilisin is of the Alpha/Beta type |
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215 | (1) |
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The active sites of subtilism and chymotrypsin are similar |
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216 | (1) |
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A structural anomaly in subtilisin has functional consequences |
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217 | (1) |
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Transition-state stabilization in subtilisin is dissected by protein engineering |
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217 | (1) |
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Catalysis occurs without a catalytic triad |
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217 | (1) |
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Substrate molecules provide catalytic groups in substrate-assisted catalysis |
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218 | (1) |
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219 | (1) |
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220 | (3) |
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223 | (28) |
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Membrane proteins are difficult to crystallize |
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224 | (1) |
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Novel crystallization methods are being developed |
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224 | (1) |
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Two-dimensional crystals of membrane proteins can be studied by electron microscopy |
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225 | (1) |
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Bacteriorhodopsin contains seven transmembrane Alpha helices |
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226 | (1) |
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Bacteriorhodopsin is a light-driven proton pump |
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227 | (1) |
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Porins form transmembrane channels by Beta strands |
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228 | (1) |
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Porins channels are made by up and down Beta barrels |
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229 | (1) |
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Each porin molecule has three channels |
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230 | (2) |
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Ion channels combine ion selectivity with high levels of ion conductance |
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232 | (1) |
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The K^(+) channel is a tetrameric molecule with one ion pore in the interface between the four subunits |
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232 | (1) |
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The ion pore has a narrow ion selectivity filter |
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233 | (1) |
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The bacterial photosynthetic reaction center is built up from four different polypetide chains and many pigments |
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234 | (2) |
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The L, M, and H subunits have transmembrane Alpha helices |
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236 | (1) |
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The photosynthetic pigments are bound to the L and M subunits |
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237 | (2) |
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Reaction centers convert light energy into electrical energy by electron flow through the membrane |
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239 | (1) |
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Antenna pigment proteins assemble into multimeric light-harvesting particles |
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240 | (1) |
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Chlorophyll molecules form circular rings in the light-harvesting complex LH2 |
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241 | (1) |
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The reaction center is surrounded by a ring of 16 antenna proteins of the light-harvesting complex LH1 |
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242 | (2) |
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Transmembrane Alpha helices can be predicted from amino acid sequences |
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244 | (1) |
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Hydrophobicity scales measure the degree of hydrophobicity of different amino acid side chains |
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245 | (1) |
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Hydropathy plots identify transmembrane helices |
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245 | (1) |
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Reaction center hydropathy plots agree with crystal structural data |
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246 | (1) |
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Membrane lipids have no specific interaction with protein transmembrane Alpha helices |
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246 | (1) |
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247 | (1) |
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248 | (3) |
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251 | (32) |
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G proteins are molecular amplifiers |
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252 | (2) |
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Ras proteins and the catalytic domain of G(Alpha) have similar three-dimensional structures |
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254 | (3) |
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G(Alpha) is activated by conformational changes of three switch regions |
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257 | (2) |
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GTPases hydrolyze GTP through nucleophilic attack by a water molecule |
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259 | (2) |
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The G(Beta) subunit has a seven-blade propeller fold, build up from seven WD repeat units |
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261 | (2) |
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The GTPase domain of G(Alpha) binds to G(Beta) in the heterotrimeric G(AlphaBetaGamma) complex |
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263 | (2) |
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Phosducin regulates light adaptation in retinal rods |
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265 | (1) |
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Phosducin binding to G(BetaGamma) blocks binding of G(Alpha) |
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265 | (2) |
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The human growth hornmone induces dimerization of its cognate receptor |
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267 | (1) |
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Dimerization of the growth hormone receptor is a sequential process |
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268 | (1) |
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The growth hormone also binds to the prolactin receptor |
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269 | (1) |
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Tyrosine kinase receptors are important enzyme-linked receptors |
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270 | (2) |
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Small protein modules form adaptors for a signaling network |
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272 | (1) |
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SH2 domains bind to phosphotyrosine-containing regions of target molecules |
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273 | (1) |
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SH3 domains bind to proline-rich regions of target molecules |
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274 | (1) |
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Src tyrosine kinases comprise SH2 and SH3 domains in addition to a tyrosine kinase |
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275 | (2) |
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The two domains of the kinase in the inactive state are held in a closed conformation by assembly of the regulatory domains |
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277 | (1) |
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278 | (2) |
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280 | (3) |
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283 | (16) |
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Collagen is a superhelix formed by three parallel, very extended left-handed helices |
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284 | (2) |
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Coiled coils are frequently used to form oligomers of fibrous and globular proteins |
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286 | (2) |
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Amyloid fibrils are suggested to be built up from continuous Beta sheet helices |
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288 | (1) |
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Spider silk is nature's high-performance fiber |
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289 | (1) |
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Muscle fibers contain myosin and actin which slide against each other during muscle contraction |
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290 | (1) |
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Myosin heads form cross-bridges between the actin and myosin filaments |
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291 | (1) |
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Time-resolved x-ray diffraction of frog muscle confirmed movement of the cross-bridges |
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292 | (1) |
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Structures of actin and myosin have been determined |
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293 | (2) |
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The structure of myosin supports the swinging cross-bridge hypothesis |
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295 | (1) |
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The role of ATP in muscular contraction has parallels to the role of GTP in G-protein activation |
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296 | (1) |
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297 | (1) |
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298 | (1) |
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15. Recognition of Foreign Molecular by the Immune System |
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299 | (26) |
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The polypeptide chains of antibodies are divided into domains |
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300 | (2) |
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Antibody diversity is generated by several different mechanisms |
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302 | (1) |
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All immunoglobulin domains have similar three-dimensional structures |
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303 | (1) |
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The immunoglobulin fold is best described as two antiparallel Beta sheets packed tightly against each other |
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304 | (1) |
|
The hypervariable regions are clustered in loop regions at one end of the variable domain |
|
|
305 | (1) |
|
The antigen-binding site is formed by close association of the hypervariable regions from both heavy and light chains |
|
|
306 | (2) |
|
The antigen-binding site binds haptens in crevices and protein antigens on large flat surfaces |
|
|
308 | (3) |
|
The CDR loops assume only a limited range of conformations, except for the heavy chain CDR3 |
|
|
311 | (1) |
|
An IgG molecule has several degrees of conformational flexibility |
|
|
312 | (1) |
|
Structures of MHC molecules have provided insights into the molecular mechanisms of T-cell activation |
|
|
312 | (1) |
|
MHC molecules are composed of antigen-binding and immunoglobulin-like domains |
|
|
313 | (1) |
|
Recognition of antigen is different in MHC molecules compared with immunoglobulins |
|
|
314 | (1) |
|
Peptides are bound differently by class I and class II MHC molecules |
|
|
315 | (1) |
|
T-cell receptors have variable and constant immunoglobulin domains and hypervariable regions |
|
|
316 | (2) |
|
MHC-peptide complexes are the ligands for T-cell receptors |
|
|
318 | (1) |
|
Many cell-surface receptors contain immunoglobulin-like domains |
|
|
318 | (2) |
|
|
|
320 | (1) |
|
|
|
321 | (4) |
|
16. The Structure of Spherical Viruses |
|
|
325 | (22) |
|
The protein shells of spherical viruses have icosahedral symmetry |
|
|
327 | (1) |
|
The icosahedron has high symmetry |
|
|
327 | (1) |
|
The simplest virus has a shell of 60 protein subunits |
|
|
328 | (1) |
|
Complex spherical viruses have more than one polypeptide chain in the asymmetric unit |
|
|
329 | (2) |
|
Structural versatility gives quasi-equivalent packing in T = 3 plant viruses |
|
|
331 | (1) |
|
The protein subunits recognize specific parts of the RNA inside the shell |
|
|
332 | (1) |
|
The protein capsid of picornaviruses contains four polypeptide chains |
|
|
333 | (1) |
|
There are four different structural proteins in picornaviruses |
|
|
334 | (1) |
|
The arrangement of subunits in the shell of picornaviruses is similar to that of T = 3 plant viruses |
|
|
334 | (1) |
|
The coat proteins of many different spherical plant and animal viruses have similar jelly roll barrel structures, indicating an evolutionary relationship |
|
|
335 | (2) |
|
Drugs against the common cold may be designed from the structure of rhinovirus |
|
|
337 | (2) |
|
Bacteriophage MS2 has a different subunit structure |
|
|
339 | (1) |
|
A dimer of MS2 subunits recognizes an RNA packaging signal |
|
|
339 | (1) |
|
The core protein of alphavirus has a chymotrypsin-like fold |
|
|
340 | (1) |
|
SV40 and polyomavirus shells are constructed from pentamers of the major coat protein with nonequivalent packing but largely equivalent interactions |
|
|
341 | (2) |
|
|
|
343 | (1) |
|
|
|
344 | (3) |
|
17. Prediction, Engineering, and Design of Protein Structures |
|
|
347 | (26) |
|
Homologous proteins have similar structure and function |
|
|
348 | (1) |
|
Homologous proteins have conserved structural cores and variable loop regions |
|
|
349 | (1) |
|
Knowledge of secondary structure is necessary for prediction of tertiary structure |
|
|
350 | (1) |
|
Prediction methods for secondary structure benefit from multiple alignment of homologous proteins |
|
|
351 | (1) |
|
Many different amino acid sequences give similar three-dimensional structures |
|
|
352 | (1) |
|
Prediction of protein structure from sequence is an unsolved problem |
|
|
352 | (1) |
|
Threading methods can assign amino acid sequences to known three-dimensional folds |
|
|
353 | (1) |
|
Proteins can be made more stable by engineering |
|
|
354 | (1) |
|
Disulfide bridges increase protein stability |
|
|
355 | (1) |
|
Glycine and proline have opposite effects on stability |
|
|
356 | (1) |
|
Stabilizing the dipoles of Alpha helices increases stability |
|
|
357 | (1) |
|
Mutants that fill cavities in hydrophobic cores do not stabilize T4 lysozyme |
|
|
358 | (1) |
|
Proteins can be engineered by combinatorial methods |
|
|
358 | (1) |
|
Phage display links the protein library to DNA |
|
|
359 | (2) |
|
Affinity and specificity of proteinase inhibitors can be optimized by phage display |
|
|
361 | (2) |
|
Structural scaffolds can be reduced in size while function is retained |
|
|
363 | (1) |
|
Phage display of random peptide libraries identified agonists of erythropoetin receptor |
|
|
364 | (1) |
|
DNA shuffling allows accelerated evolution of genes |
|
|
365 | (2) |
|
Protein structures can be designed from first principles |
|
|
367 | (1) |
|
A Beta structure has been converted to an Alpha structure by changing only half of the sequence |
|
|
368 | (2) |
|
|
|
370 | (1) |
|
|
|
371 | (2) |
|
18. Determination of Protein Structures |
|
|
373 | (20) |
|
Several different techniques are used to study the structure of protein molecules |
|
|
373 | (1) |
|
Protein crystals are difficult to grow |
|
|
374 | (2) |
|
X-ray sources are either monochromatic or polychromatic |
|
|
376 | (1) |
|
X-ray data are recorded either on image plates or by electronic detectors |
|
|
377 | (1) |
|
The rules for diffraction are given by Bragg's law |
|
|
378 | (1) |
|
Phase determination is the major crystallographic problem |
|
|
379 | (2) |
|
Phase information can also be obtained by Multiwavelength Anomalous Diffraction experiments |
|
|
381 | (1) |
|
Building a model involves subjective interpretation of the data |
|
|
381 | (2) |
|
Errors in the initial model are removed by refinement |
|
|
383 | (1) |
|
Recent technological advances have greatly influenced protein crystallography |
|
|
383 | (1) |
|
X-ray diffraction can be used to study the structure of fibers as well as crystals |
|
|
384 | (2) |
|
The structure of biopolymers can be studied using fiber diffraction |
|
|
386 | (1) |
|
NMR methods use the magnetic properties of atomic nuclei |
|
|
387 | (2) |
|
Two-dimensional NMR spectra of proteins are interpreted by the method of sequential assignment |
|
|
389 | (1) |
|
Distance constraints are used to derive possible structures of a protein molecule |
|
|
390 | (1) |
|
Biochemical studies and molecular structure give complementary functional information |
|
|
391 | (1) |
|
|
|
391 | (1) |
|
|
|
392 | (1) |
| Protein Structure on the World Wide Web |
|
393 | |
