Roles of bacillus subtilis Dpra and Ssba in RecA-mediated genetic recombination

Yadav, T., Carrasco, B., Serrano, E. and Alonso, J. C. (2014) Roles of bacillus subtilis Dpra and Ssba in RecA-mediated genetic recombination. Journal of Biological Chemistry, 289(40), pp. 27640-27652. (doi: 10.1074/jbc.M114.577924) (PMID:25138221) (PMCID:PMC4183802)

Abstract

Bacillus subtilis competence-induced RecA, SsbA, SsbB, and DprA are required to internalize and to recombine single-stranded (ss) DNA with homologous resident duplex. RecA, in the ATP·Mg2+-bound form (RecA·ATP), can nucleate and form filament onto ssDNA but is inactive to catalyze DNA recombination. We report that SsbA or SsbB bound to ssDNA blocks the RecA filament formation and fails to activate recombination. DprA facilitates RecA filamentation; however, the filaments cannot engage in DNA recombination. When ssDNA was preincubated with SsbA, but not SsbB, DprA was able to activate DNA strand exchange dependent on RecA·ATP. This work demonstrates that RecA·ATP, in concert with SsbA and DprA, catalyzes DNA strand exchange, and SsbB is an accessory factor in the reaction. In contrast, RecA·dATP efficiently catalyzes strand exchange even in the absence of single-stranded binding proteins or DprA, and addition of the accessory factors marginally improved it. We proposed that the RecA-bound nucleotide (ATP and to a lesser extent dATP) might dictate the requirement for accessory factors.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Serrano, Dr Ester
• Authors: Yadav, T., Carrasco, B., Serrano, E., and Alonso, J. C.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Journal of Biological Chemistry
• Publisher: American Society for Biochemistry and Molecular Biology
• ISSN: 0021-9258
• ISSN (Online): 1083-351X
• Published Online: 19 August 2014
• Copyright Holders: Copyright © 2014 ASBMB
• First Published: First published in Journal of Biological Chemistry 289(40): 27640-27652
• Publisher Policy: Reproduced under a Creative Commons License