Goyal, K. and Qamra, R. and Mande, S.C. (2006) Multiple Gene Duplication and Rapid Evolution in the groEL Gene: Functional Implications. Journal of Molecular Evolution, 63 (6). pp. 781-787. ISSN 0022-2844

Text J Mol Evol 63 p781.pdf Restricted to Repository staff only Download (209Kb) | Request a copy

Abstract

The chaperonins, GroEL and GroES, are present ubiquitously and provide a paradigm in the understanding of assisted protein folding. Due to its essentiality of function, GroEL exhibits high sequence conservation across species. Complete genome sequencing has shown the occurrence of duplicate or multiple copies of groEL genes in bacteria such as Mycobacterium tuberculosis and Corynebacterium glutamicum. Monophyly of each bacterial clade in the phylogenetic tree generated for the GroEL protein suggests a lineage-specific duplication. The duplicated groEL gene in Actinobacteria is not accompanied by the operonic groES despite the presence of upstream regulatory elements. Our analysis suggests that in these bacteria the duplicated groEL genes have undergone rapid evolution and divergence to function in a GroES-independent manner. Evaluation of multiple sequence alignment demonstrates that the duplicated genes have acquired mutations at functionally significant positions including those involved in substrate binding, ATP binding, and GroES binding and those involved in inter-ring and intra-ring interactions. We propose that the duplicate groEL genes in different bacterial clades have evolved independently to meet specific requirements of each clade. We also propose that the groEL gene, although essential and conserved, accumulates nonconservative substitutions to exhibit structural and functional variations.

Item Type:	Article
Depositing User:	Users 2 not found.
Date Deposited:	20 Oct 2015 11:02
Last Modified:	20 Oct 2015 11:02
URI:	http://cdfd.sciencecentral.in/id/eprint/558

Actions (login required)

View Item