Turns in Proteins: Difference between revisions
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Gamma turns consist of three residues and contain a hydrogen bond between residues one and three. In a search of 54 proteins nine proteins were found to have eleven classic γ-turns, and these eleven turns had mean phi and psi values at residue ''i'' + 1 of +75.0 and -64, respectively.<ref name="Miner">Miner-White, EJ, et. al. ''One type of gamma turn, rather than the other, gives rise to chain reversal in proteins''. J. Mol. Bio. '''204''', 1983, pp. 777-782.</ref> Seven of these eleven turns are involved in the formation of β-hairpins which produce a reversal in the peptide chain. Several examples of β-hairpins follow: | Gamma turns consist of three residues and contain a hydrogen bond between residues one and three. In a search of 54 proteins nine proteins were found to have eleven classic γ-turns, and these eleven turns had mean phi and psi values at residue ''i'' + 1 of +75.0 and -64, respectively.<ref name="Miner">Miner-White, EJ, et. al. ''One type of gamma turn, rather than the other, gives rise to chain reversal in proteins''. J. Mol. Bio. '''204''', 1983, pp. 777-782.</ref> Seven of these eleven turns are involved in the formation of β-hairpins which produce a reversal in the peptide chain. Several examples of β-hairpins follow: | ||
* <scene name='Turns_in_Proteins/2alp_classic/3'>Alpha-Lytic protease</scene>; <scene name='Turns_in_Proteins/2alp_classic2/2'>Isolated turn</scene> | * <scene name='Turns_in_Proteins/2alp_classic/3'>Alpha-Lytic protease</scene>; <scene name='Turns_in_Proteins/2alp_classic2/2'>Isolated turn</scene> | ||
* <scene name='Turns_in_Proteins/Proteinase_a/ | * <scene name='Turns_in_Proteins/Proteinase_a/4'>Proteinase A</scene>; <scene name='Turns_in_Proteins/Proteinase_a2/3'>Isolate Turn</scene> | ||
* <scene name='Turns_in_Proteins/Thermolysin/2'>Thermolysin</scene>; <scene name='Turns_in_Proteins/Thermolysin2/2'>Isolated turn</scene> - Unusual because it has two hbonds. | * <scene name='Turns_in_Proteins/Thermolysin/2'>Thermolysin</scene>; <scene name='Turns_in_Proteins/Thermolysin2/2'>Isolated turn</scene> - Unusual because it has two hbonds. | ||