Title: Analysis of the relationship between side-chain conformation and secondary structure in globular proteins
Abstract: The relationship between the preferred side-chain dihedral angles and the secondary structure of a residue was examined. The structures of 61 proteins solved to a resolution of 2.0 Å (I Å = 0.1 nm) or better were analysed using a relational database to store the information. The strongest feature observed was that the χ1 distribution for most sidechains in an α-helix showed an absence of the g− conformation and a shift towards the t conformation when compared to the non-αβ structures. The exceptions to this tendency were for short polar side-chains that form hydrogen bonds with the main-chain which prefer g+. Shifts in the χ1 preferences for residues in the β-sheet were observed. Other side-chain dihedral angles (χ2, χ3, χ4) were found to be influenced by the main-chain. This paper presents more accurate distributions for the side-chain dihedral angles which were obtained from the increased number of proteins determined to high resolution. The means and standard deviations for χ1 and χ2 angles are presented for all residues according to the secondary structure of the main-chain. The means and standard deviations are given for the most popular conformations for side-chains in which χ3 and χ4 rotations affect the position of C atoms.
Publication Year: 1987
Publication Date: 1987-11-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 419
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