title: Inhibition of bacterial DNA cytosine-5-methyltransferase by S-adenosyl-L-homocysteine and some related compounds.
abstract: S-Adenosyl-L-homocysteine and five related compounds have been evaluated as inhibitors of a DNA cytosine-5-methyltransferase. DNA methylation was assayed in cell extracts from E. coli strain J6-2 dcm+, proficient in DNA cytosine-5-methyltransferase activity, containing substrate DNA isolated from E. coli strain J6-2 dcm-, a strain deficient in DNA cytosine-5-methyltransferase. S-Adenosyl-L-homocysteine and its 7-deaza analogue, S-tubercidinylhomocysteine, were competitive inhibitors of DNA cytosine-5-methyltransferase with Ki's of 14.2 and 17.6 microM, respectively, in the above enzyme assay.
mesh_terms: D004248:DNA (Cytosine-5-)-Methyltransferases / Q000037:antagonists & inhibitors*; D004926:Escherichia coli / Q000201:enzymology*; D006710:Homocysteine / Q000031:analogs & derivatives*; D007700:Kinetics; D008780:Methyltransferases / Q000037:antagonists & inhibitors*; D009154:Mutation; D012435:S-Adenosylhomocysteine / Q000494:pharmacology*
chemical_list: D006710:Homocysteine; D012435:S-Adenosylhomocysteine; D008780:Methyltransferases; D004248:DNA (Cytosine-5-)-Methyltransferases