Structural Features and Functional Dependency on β-Clamp Define Distinct Subfamilies of Bacterial Mismatch Repair Endonuclease MutL.

ABSTRACT: In early reactions of DNA mismatch repair, MutS recognizes mismatched bases and activates MutL endonuclease to incise the error-containing strand of the duplex. DNA sliding clamp is responsible for directing the MutL-dependent nicking to the newly synthesized/error-containing strand. In Bacillus subtilis MutL, the β-clamp-interacting motif (β motif) of the C-terminal domain (CTD) is essential for both in vitro direct interaction with β-clamp and in vivo repair activity. A large cluster of negatively charged residues on the B. subtilis MutL CTD prevents nonspecific DNA binding until β clamp interaction neutralizes the negative charge. We found that there are some bacterial phyla whose MutL endonucleases lack the β motif. For example, the region corresponding to the β motif is completely mis

SUBMITTER: Fukui K 

PROVIDER: S-EPMC5016104 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature