Premium
Mismatch repair causes the dynamic release of an essential DNA polymerase from the replication fork
Author(s) -
Klocko Andrew D.,
Schroeder Jeremy W.,
Walsh Brian W.,
Lenhart Justin S.,
Evans Margery L.,
Simmons Lyle A.
Publication year - 2011
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2011.07841.x
Subject(s) - biology , processivity , dna replication , dna polymerase , dna mismatch repair , replication protein a , dna clamp , dna polymerase delta , control of chromosome duplication , dna polymerase ii , microbiology and biotechnology , genetics , dna repair , dna , gene , dna binding protein , reverse transcriptase , polymerase chain reaction , transcription factor
Summary Mismatch repair (MMR) corrects DNA polymerase errors occurring during genome replication. MMR is critical for genome maintenance, and its loss increases mutation rates several hundred fold. Recent work has shown that the interaction between the mismatch recognition protein MutS and the replication processivity clamp is important for MMR in Bacillus subtilis . To further understand how MMR is coupled to DNA replication, we examined the subcellular localization of MMR and DNA replication proteins fused to green fluorescent protein (GFP) in live cells, following an increase in DNA replication errors. We demonstrate that foci of the essential DNA polymerase DnaE–GFP decrease following mismatch incorporation and that loss of DnaE–GFP foci requires MutS. Furthermore, we show that MutS and MutL bind DnaE in vitro , suggesting that DnaE is coupled to repair. We also found that DnaE–GFP foci decrease in vivo following a DNA damage‐independent arrest of DNA synthesis showing that loss of DnaE–GFP foci is caused by perturbations to DNA replication. We propose that MutS directly contacts the DNA replication machinery, causing a dynamic change in the organization of DnaE at the replication fork during MMR. Our results establish a striking and intimate connection between MMR and the replicating DNA polymerase complex in vivo .