Molecular determinants of the DprA-RecA interaction for nucleation on ssDNA

Johnny Lisboa, Jessica Andreani, Dyana Sanchez, Marion Boudes, Bruno Collinet, Dominique Liger, Herman van Tilbeurgh, Raphael Guerois, Sophie Quevillon-Cheruel

Research output: Contribution to journalArticleResearchpeer-review

16 Citations (Scopus)

Abstract

Natural transformation is a major mechanism of horizontal gene transfer in bacteria that depends on DNA recombination. RecA is central to the homologous recombination pathway, catalyzing DNA strand invasion and homology search. DprA was shown to be a key binding partner of RecA acting as a specific mediator for its loading on the incoming exogenous ssDNA. Although the 3D structures of both RecA and DprA have been solved, the mechanisms underlying their cross-talk remained elusive. By combining molecular docking simulations and experimental validation, we identified a region on RecA, buried at its self-assembly interface and involving three basic residues that contact an acidic triad of DprA previously shown to be crucial for the interaction. At the core of these patches, (DprA)M238 and (RecA)F230 are involved in the interaction. The other DprA binding regions of RecA could involve the N-terminal alpha-helix and a DNA-binding region. Our data favor a model of DprA acting as a cap of the RecA filament, involving a DprA-RecA interplay at two levels: their own oligomeric states and their respective interaction with DNA. Our model forms the basis for a mechanistic explanation of how DprA can act as a mediator for the loading of RecA on ssDNA.
Original languageEnglish
Pages (from-to)7395 - 7408
Number of pages14
JournalNucleic Acids Research
Volume42
Issue number11
DOIs
Publication statusPublished - 2014

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