ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Mycobacterium leprae RecA is structurally analogous but functionally distinct from Mycobacterium tuberculosis RecA protein

Patil, Neelakanteshwar K and Singh, Pawan and Harsha, Sri and Muniyappa, K (2011) Mycobacterium leprae RecA is structurally analogous but functionally distinct from Mycobacterium tuberculosis RecA protein. In: Biochimica et Biophysica Acta (BBA) - Proteins & Proteomics, 1814 (12). pp. 1802-1811.

[img] PDF
Mycobacterium.pdf - Published Version
Restricted to Registered users only

Download (2MB) | Request a copy
Official URL: http://dx.doi.org/10.1016/j.bbapap.2011.09.011

Abstract

Mycobacterium leprae is closely related to Mycobacterium tuberculosis, yet causes a very different illness. Detailed genomic comparison between these two species of mycobacteria reveals that the decaying M. leprae genome contains less than half of the M. tuberculosis functional genes. The reduction of genome size and accumulation of pseudogenes in the M. leprae genome is thought to result from multiple recombination events between related repetitive sequences, which provided the impetus to investigate the recombination-like activities of RecA protein. In this study, we have cloned, over-expressed and purified M. leprae RecA and compared its activities with that of M. tuberculosis RecA. Both proteins, despite being 91% identical at the amino acid level, exhibit strikingly different binding profiles for single-stranded DNA with varying GC contents, in the ability to catalyze the formation of D-loops and to promote DNA strand exchange. The kinetics and the extent of single-stranded DNA-dependent ATPase and coprotease activities were nearly equivalent between these two recombinases. However, the degree of inhibition exerted by a range of ATP:ADP ratios was greater on strand exchange promoted by M. leprae RecA compared to its M. tuberculosis counterpart. Taken together, our results provide insights into the mechanistic aspects of homologous recombination and coprotease activity promoted by M. lepare RecA, and further suggests that it differs from the M. tuberculosis counterpart. These results are consistent with an emerging concept of DNA-sequence influenced structural differences in RecA nucleoprotein filaments and how these differences reflect on the multiple activities associated with RecA protein. (C) 2011 Elsevier B.V. All rights reserved.

Item Type: Journal Article
Additional Information: Copyright of this article belongs to Elsevier Science B.V.
Keywords: Mycobacterium;RecA;Gene decay;DNA strand exchange;ATPase;SOS response
Department/Centre: Division of Biological Sciences > Biochemistry
Depositing User: Id for Latest eprints
Date Deposited: 30 Jan 2012 08:56
Last Modified: 30 Jan 2012 08:56
URI: http://eprints.iisc.ac.in/id/eprint/43163

Actions (login required)

View Item View Item