Journal of Biological Chemistry
Volume 281, Issue 8, 24 February 2006, Pages 4708-4717
Journal home page for Journal of Biological Chemistry

DNA: Replication, Repair, and Recombination
Inhibition of RecA Protein Function by the RdgC Protein from Escherichia coli*

https://doi.org/10.1074/jbc.M513592200Get rights and content
Under a Creative Commons license
open access

The Escherichia coli RdgC protein is a potential negative regulator of RecA function. RdgC inhibits RecA protein-promoted DNA strand exchange, ATPase activity, and RecA-dependent LexA cleavage. The primary mechanism of RdgC inhibition appears to involve a simple competition for DNA binding sites, especially on duplex DNA. The capacity of RecA to compete with RdgC is improved by the DinI protein. RdgC protein can inhibit DNA strand exchange catalyzed by RecA nucleoprotein filaments formed on single-stranded DNA by binding to the homologous duplex DNA and thereby blocking access to that DNA by the RecA nucleoprotein filaments. RdgC protein binds to single-stranded and double-stranded DNA, and the protein can be visualized on DNA using electron microscopy. RdgC protein exists in solution as a mixture of oligomeric states in equilibrium, most likely as monomers, dimers, and tetramers. This concentration-dependent change of state appears to affect its mode of binding to DNA and its capacity to inhibit RecA. The various species differ in their capacity to inhibit RecA function.

Cited by (0)

*

This work was supported by Grant GM52725 from the National Institutes of General Medical Sciences (to M. M. C. and R. B. I.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental text and references.