beta_turn
A motif of four consecutive residues that may contain one H-bond, which, if present, is between the main-chain CO of the first residue and the main-chain NH of the fourth. It is characterized by the dihedral angles of the second and third residues, which are the basis for sub-categorization.
SO:0001128
polypeptide_turn_motif
is_a
beta turn
exact