β Clamp Directs Localization of Mismatch Repair in Bacillus subtilis

• Main Authors: Simmons, Lyle A. (Contributor), Davies, Bryan W. (Contributor), Walker, Graham C. (Contributor), Grossman, Alan Davis (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Biology (Contributor), Grossman, Alan D. (Contributor)
• Format: Article
• Language: English
• Published: Elsevier, 2014-01-10T14:50:47Z.
• Subjects: Article
• Online Access: Get fulltext

MutS homologs function in several cellular pathways including mismatch repair (MMR), the process by which mismatches introduced during DNA replication are corrected. We demonstrate that the C terminus of Bacillus subtilis MutS is necessary for an interaction with β clamp. This interaction is required for MutS-GFP focus formation in response to mismatches. Reciprocally, we show that a mutant of the β clamp causes elevated mutation frequencies and is reduced for MutS-GFP focus formation. MutS mutants defective for interaction with β clamp failed to support the next step of MMR, MutL-GFP focus formation. We conclude that the interaction between MutS and β is the major molecular interaction facilitating focus formation and that β clamp aids in the stabilization of MutS at a mismatch in vivo. The striking ability of the MutS C terminus to direct focus formation at replisomes by itself, suggests that it is mismatch recognition that licenses MutS's interaction with β clamp.
National Cancer Institute (U.S.) (Grant CA21615-27)
Massachusetts Institute of Technology. Center for Environmental Health Sciences
National Institutes of Health (U.S.) (Grant GM41934)
National Cancer Institute (U.S.) (Postdoctoral Fellowship)