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Interaction Interfaces of Protein Domains Are Not Topologically Equivalent Across Families Within Superfamilies: Implications for Metabolic and Signaling Pathways

Rekha, N and Machado, SM and Narayanan, C and Krupa, A and Srinivasan, N (2004) Interaction Interfaces of Protein Domains Are Not Topologically Equivalent Across Families Within Superfamilies: Implications for Metabolic and Signaling Pathways. In: Proteins: Structure, Function, and Bioinformatics, 58 (2). pp. 339-353.

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Abstract

Using a data set of aligned protein domain superfamilies of known three-dimensional structure, we compared the location of interdomain interfaces on the tertiary folds between members of distantly related protein domain superfamilies. The data set analyzed is comprised of interdomain interfaces, with domains occurring within a polypeptide chain and those between two polypeptide chains. We observe that, in general, the interfaces between protein domains are formed entirely in different locations on the tertiary folds in such pairs. This variation in the location of interface happens in protein domains involved in a wide range of functions, such as enzymes, adapters, and domains that bind protein ligands, or cofactors. While basic biochemical functionality is preserved at the domain superfamily level, the effect of biochemical function on protein assemblies is different in these protein domains related by superfamily. The divergence between proteins, in most cases, is coupled with domain recruitment, with different modes of interaction with the recruited domain. This is in complete contrast to the observation that in closely related homologous protein domains, almost always the interaction interfaces are topologically equivalent. In a small subset of interacting domains within proteins related by remote homology, we observe that the relative positioning of domains with respect to one another is preserved. Based on the analysis of multidomain proteins of known or unknown structure, we suggest that variation in protein-protein interactions in members within a superfamily could serve as diverging points in otherwise parallel metabolic or signaling pathways. We discuss a few representative cases of diverging pathways involving domains in a superfamily.

Item Type: Journal Article
Additional Information: The copyright of this article belongs to Wiley Inter Science.
Keywords: homologous proteins;molecular recognition;protein domain superfamilies;protein evolution;protein-protein interactions
Department/Centre: Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited: 24 Mar 2006
Last Modified: 19 Sep 2010 04:24
URI: http://eprints.iisc.ernet.in/id/eprint/5870

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