Methylation-Induced Hypermutation in Natural Populations of Bacteria.

ABSTRACT: Methylation of DNA at the C-5 position of cytosine occurs in diverse organisms. This modification can increase the rate of C→T transitions at the methylated position. In Escherichia coli and related enteric bacteria, the inner C residues of the sequence CCWGG (W is A or T) are methylated by the Dcm enzyme. These sites are hot spots of mutation during rapid growth in the laboratory but not in nondividing cells, in which repair by the Vsr protein is effective. It has been suggested that hypermutation at these sites is a laboratory artifact and does not occur in nature. Many other methyltransferases, with a variety of specificities, can be found in bacteria, usually associated with restriction enzymes and confined to a subset of the population. Their methylation targets are also possib

SUBMITTER: Cherry JL 

PROVIDER: S-EPMC6256030 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature