Visualization of mismatch repair in bacterial cells.
We determined the localizations of mismatch repair proteins in living Bacillus subtilis cells. MutS-GFP colocalized with the chromosome in all cells and formed foci in a subset of cells. MutL-GFP formed foci in a subset of cells, and its localization was MutS dependent. The introduction of mismatches by growth in 2-aminopurine caused a replication-dependent increase in the number of cells with MutS and MutL foci. Approximately half of the MutS foci colocalized with DNA polymerase foci. We conclude that MutS is associated with the entire chromosome, poised to detect mismatches. After detection, it appears that mismatch repair foci assemble at mismatches as they emerge from the DNA polymerase and are then carried away from the replisome by continuing replication.
Smith
B T
BT
Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Grossman
A D
AD
Walker
G C
GC
D015075:2-Aminopurine / Q000494:pharmacology; D000251:Adenosine Triphosphatases; D001412:Bacillus subtilis / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020137:Base Pair Mismatch / Q000187:drug effects / Q000235:genetics*; D002470:Cell Survival; D002701:Chloramphenicol / Q000494:pharmacology; D002876:Chromosomes, Bacterial / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics; D004261:DNA Replication / Q000187:drug effects; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D029968:Escherichia coli Proteins; D008853:Microscopy; D008957:Models, Genetic; D000070956:MutL Proteins; D051719:MutS DNA Mismatch-Binding Protein; D009154:Mutation / Q000235:genetics; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C074770:MutL protein, E coli; D011993:Recombinant Fusion Proteins; D015075:2-Aminopurine; D002701:Chloramphenicol; D004259:DNA-Directed DNA Polymerase; D000251:Adenosine Triphosphatases; D000070956:MutL Proteins; D051719:MutS DNA Mismatch-Binding Protein; C497175:MutS protein, E coli