β- and γ-turns in proteins revisited: A new set of amino acid turn-type dependent positional preferences and potentials

摘要

The number of β-turns in a representative set of 426 protein three-dimensional crystal structures selected from the recent Protein Data Bank has nearly doubled and the number of γ-turns in a representative set of 320 proteins ha increased over seven times since the previous analysis. β-turns (7153) and γ-turns (991) extracted from these proteins were used to derive a revised set of type-dependent amino acid positional preferences and potentials. Compared with previous results, the preference for proline, methionine and tryptophan ha increased and the Preference for glutamine, valine, glutamic acid and alanine has decreased for β-turns.