Disease relevance of mutH

• The complete nucleotide sequence of mutH gene from E. coli has been determined [1].
• H. pylori gastritis is more frequent in patients with microsatellite instability-positive gastric cancers, and H. pylori organisms independently of inflammation can reduce DNA mismatch repair protein levels, raising the hypothesis that H. pylori organisms might lead to mutagenesis during infection [2].

High impact information on mutH

• Such deletions are also found with starved bacteria defective in methyl-directed mismatch correction activity (mutH, mutL or mutS), and deletion mutations are also found among the much lower number of mutants that arise in bacteria wild-type for mismatch correction [3].
• This is supported herein by showing that like dnaC1331, a priB mutation is synthetically lethal with a dam mutation and this can be rescued by a mutH mutation [4].
• Deletion analysis of the DNA sequences upstream of mutH has identified the promoter region for this gene [1].
• The dam-2 mutant strain exhibits a level of sensitivity to 2-aminopurine (2AP) intermediate between that of the dam+ and the DNA adenine methylation-deficit dam-1 strain, and 2AP sensitivity was reversed by introduction of a mutH mutation or of the plasmid pMQ148 (which carries a functional Escherichia coli dam+ gene) [5].

References