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On residues in the disallowed region of the Ramachandran map
Author(s) -
Pal Debnath,
Chakrabarti Pinak
Publication year - 2002
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10051
Subject(s) - ramachandran plot , chemistry , residue (chemistry) , stereochemistry , crystallography , amino acid residue , peptide , protein structure , peptide sequence , biochemistry , gene
An analysis of the occurrence of nonglycyl residues in conformations disallowed in the Ramachandran plot is presented. Ser, Asn, Thr, and Cys have the highest propensities to exhibit such conformations, and the branched aliphatic residues the lowest. Residues cluster in five regions and there are some trends in the types of residues and their side‐chain conformations (χ 1 ) occupying these. Majority of the residues are found at the edge of helices and strands and in short loops, and are involved in different types of weak, stabilizing interactions. A structural motif has been identified where a residue in disallowed conformation occurs as the first residue of a short 3 10 ‐helix. On the basis of the types of neighboring residues, the location in the three‐dimensional structure and accessibility, there are similarities with the occurrence of cis peptide bonds in protein structures. © 2002 John Wiley & Sons, Inc. Biopolymers 63: 195–206, 2002; DOI 10.1002/bip.10051