The effect of flanking sequences on the de novo methylation of C-G pairs by the human DNA methylase.
The HeLa DNA methylase can methylate selected cytosine residues in oligodeoxynucleotides as small as 12-16 nucleotides in length in vitro. The maximum methylation rate seems to require oligomers having more than one C-G in the molecule even when only one of the C-G pairs is methylated. Compounds which contain a high G+C content also seem to be favored substrates. The use of defined synthetic oligodeoxynucleotides permits one to demonstrate that flanking DNA sequences can be critical in determining whether a C-G site can be methylated.
D001482:Base Composition; D001483:Base Sequence; D003596:Cytosine; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D006147:Guanine; D006367:HeLa Cells / Q000201:enzymology; D006801:Humans; D007700:Kinetics; D008745:Methylation; D013379:Substrate Specificity
D006147:Guanine; D003596:Cytosine; D004248:DNA (Cytosine-5-)-Methyltransferases