title: Inducible repair of phosphotriesters in Escherichia coli.
abstract: Extracts from Escherichia coli cells induced for the adaptive response have been prepared that are capable of repairing O6-methylguanine, O4-methylthymine, and the phosphotriesters produced on the DNA backbone by alkylating agents such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The phosphotriesters are repaired by a methyltransferase distinct from the one that demethylates O6-methylguanine. We propose that this increased capacity to repair phosphotriesters accounts for much of the increased resistance to MNNG toxicity seen in cultures induced for the adaptive response.
mesh_terms: D004260:DNA Repair; D003854:Deoxyribonucleotides / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics*; D007700:Kinetics; D008745:Methylation; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D003854:Deoxyribonucleotides; D008769:Methylnitronitrosoguanidine; D008780:Methyltransferases