since this dna is at least partially methylated in vivo and serves as an excellent substrate for methylation in vitro , hypomethylation of dna in analog-treated cells appears to result from the loss of dna methyltransferase , rather than from an inherent inability of 5-azacytosine- substituted dna to serve as a methyl acceptor .
C0025723
methylation
C0012873
dna methyltransferase