The suicidal DNA repair methyltransferases of microbes.
Virtually every organism so far tested has been found to possess an extremely efficient DNA repair mechanism to ensure that certain alkylated oxygens do not accumulate in the genome. The repair is executed by DNA methyltransferases (MTases) which repair DNA O6-methylguanine (O6MeG), O4-methylthymine (O4MeT) and methylphosphotriesters (MePT). The mechanism is rather extravagant because an entire protein molecule is expended for the repair of just one, or sometimes two, O-alkyl DNA adduct(s). Cells profit from such an expensive transaction by earning protection against death and mutation by alkylating agents. This review considers the structure, function and biological roles of a number of well-characterized microbial DNA repair MTases.
Samson
L
L
Department of Molecular and Cellular Toxicology, Harvard School of Public Health, Boston, Massachusetts 02115.
D000595:Amino Acid Sequence; D015254:DNA Modification Methylases / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data
D015254:DNA Modification Methylases