ANALYSIS OF THE RELATIONSHIP BETWEEN SIDE-CHAIN CONFORMATION AND SECONDARY STRUCTURE IN GLOBULAR-PROTEINS
ANALYSIS OF THE RELATIONSHIP BETWEEN SIDE-CHAIN CONFORMATION AND SECONDARY STRUCTURE IN GLOBULAR-PROTEINS
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DOI:
10.1016/0022-2836(87)90314-7
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发表时间:
1987-11-20
影响因子:
5.6
通讯作者:
STERNBERG, MJE
中科院分区:
文献类型:
--
作者:
MCGREGOR, MJ;ISLAM, SA;STERNBERG, MJE
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 .ANG. (1 .ANG. = 0.1 nm) or better were analysed using a relational database to store the information. The strongest feature observed was that the .chi.1 distribution for most side-chains in an .alpha.-helix showed an absence of the g- conformation and a shift towards the t conformation when compared to the non-.alpha./.beta. 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 .chi.1 preferences for residues in the .beta.-sheet were observed. Other side-chain dihedral angles (.chi.2, .chi.3, .chi.4) 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 .chi.1 and .chi.2 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 .chi.3 and .chi.4 rotations affect the position of C atoms.