A DNA methyltransferase can protect the genome from postdisturbance attack by a restriction-modification gene complex.

ABSTRACT: In prokaryotic genomes, some DNA methyltransferases form a restriction-modification gene complex, but some others are present by themselves. Dcm gene product, one of these orphan methyltransferases found in Escherichia coli and related bacteria, methylates DNA to generate 5'-C(m)CWGG just as some of its eukaryotic homologues do. Vsr mismatch repair function of an adjacent gene prevents C-to-T mutagenesis enhanced by this methylation but promotes other types of mutation and likely has affected genome evolution. The reason for the existence of the dcm-vsr gene pair has been unclear. Earlier we found that several restriction-modification gene complexes behave selfishly in that their loss from a cell leads to cell killing through restriction attack on the genome. There is also increasing evide

SUBMITTER: Takahashi N 

PROVIDER: S-EPMC151934 | biostudies-literature | 2002 Nov

REPOSITORIES: biostudies-literature