Open AccessReduction of GC → TA Transversion Mutation by Overexpression of MutS in Escherichia coli K-12
Author(s) -
Jing Zhao,
Malcolm E. Winkler
Publication year - 2000
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.182.17.5025-5028.2000
Subject(s) - transversion , biology , escherichia coli , mutant , mutation , dna mismatch repair , microbiology and biotechnology , lac operon , dna , dna repair , genetics , gene
Overexpression of the MutS repair protein significantly decreased the rate oflacZ GC → TA transversion mutation in stationary-phase and exponentially growing bacteria and inmutY andmutM mutants, which accumulate mismatches between 8-oxoguanine (8-oxoG) and adenine residues in DNA. Conversely, GC → TA transversion increased inmutL ormutS mutants in stationary phase. In contrast, overexpression of MutS did not appreciably reducelacZ AT → CG transversion mutation in amutT mutant. These results suggest that MutS-dependent repair can correct 8-oxoG:A mismatches inEscherichia coli cells but may not be able to compete with mutation fixation by MutY inmutT mutants.