[Methylcobalamin-dependent enzymatic methylation of DNA in a cell-free extract of Propionibacterium shermanii].
The regulation of the functional activity of Propionibacterium shermanii cells by cobalamin is accompanied by an increase in the methylation of their DNA at the cytosine residue: the DNA from B12-deficient cells is undermethylated as compared with the DNA from control cells, i. e. cells synthesizing corrinoids. The results of in vitro experiments make it possible to correlate this phenomenon with the capability of DNA methylases from B12-deficient and control cells to function with different donors of methyl groups. Just as the enzymes methylating adenine and cytosine in B12-deficient cells, adenine DNA methylase from cells synthesizing corrinoids is active in vitro with S-adenosylmethionine. Cytosine DNA methylase from P. shermanii control cells is inactive with S-adenosylmethionine and transfers methyl groups only in the presence of cobalamins.
D003470:Culture Media / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism*; D008745:Methylation; D011424:Propionibacterium / Q000378:metabolism*; D014805:Vitamin B 12 / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism
D003470:Culture Media; D004269:DNA, Bacterial; C019476:mecobalamin; D004248:DNA (Cytosine-5-)-Methyltransferases; D014805:Vitamin B 12
Zavisimoe ot metilkobalamina énzimaticheskoe metilirovanie DNK v beskletochnom éktsrakte Propionibacterium shermanii.