title: Case study on the evolution of hetero-oligomer interfaces based on the differences in paralogous proteins.
abstract: We addressed the evolutionary trace of hetero-oligomer interfaces by comparing the structures of paralogous proteins; one of them is a monomer or homo-oligomer and the other is a hetero-oligomer. We found different trends in amino acid conservation pattern and hydrophobicity between homo-oligomer and hetero-oligomer. The degree of amino acid conservation in the interface of homo-oligomer has no obvious difference from that in the surface, whereas the degree of conservation is much higher in the interface of hetero-oligomer. The interface of homo-oligomer has a few very conserved residue positions, whereas the residue conservation in the interface of hetero-oligomer tends to be higher. In addition, the interface of hetero-oligomer has a tendency of being more hydrophobic compared with the one in homo-oligomer. We conjecture that these differences are related to the inherent symmetry in homo-oligomers that cannot exist in hetero-oligomers. Paucity of the structural data precludes statistical tests of these tendencies, yet the trend can be applied to the prediction of the interface of hetero-oligomer. We obtained putative interfaces of the subunits in CPSF (cleavage and polyadenylation specificity factor), one of the human pre-mRNA 3'-processing complexes. The locations of predicted interface residues were consistent with the known experimental data.
authors: Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo, Tokyo 112-8610, Japan.
authors: Saki
authors: S
authors: Aoto
authors: Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo, Tokyo 112-8610, Japan; Centre for Informational Biology, Ochanomizu University, Bunkyo, Tokyo 112-8610, Japan; National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.
authors: Kei
authors: K
authors: Yura
keywords: CPSF; Kyte and Doolittle parameter; paralogues; sequence conservation; subunit interface