A constitutive O6-methylguanine-DNA methyltransferase of Rhizobium meliloti |
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| Authors: | A Kaufman G C Walker |
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| Affiliation: | Biology Department, Massachusetts Institute of Technology, Cambridge 02139. |
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| Abstract: | 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. |
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