A constitutive O6-methylguanine-DNA methyltransferase of Rhizobium meliloti.
We have identified a DNA methyltransferase activity of the nitrogen-fixing bacterium, Rhizobium meliloti, that repairs O6-methylguanine lesions. Repair of the O6-methylguanine residue results in transfer of the methyl group to a cysteine residue of a 28,000-dalton protein. The O6-methyltransferase activity is expressed constitutively and R. meliloti does not exhibit an adaptive response to alkylating agents.
Biology Department, Massachusetts Institute of Technology, Cambridge 02139.
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Kaufman
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Walker
D004260:DNA Repair; D004269:DNA, Bacterial / Q000187:drug effects / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D008745:Methylation; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D008780:Methyltransferases / Q000378:metabolism*; D009154:Mutation; D019853:O(6)-Methylguanine-DNA Methyltransferase; D012231:Rhizobium / Q000201:enzymology* / Q000235:genetics
D004269:DNA, Bacterial; D008769:Methylnitronitrosoguanidine; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase