Fig. 1.

Methylated deoxyadenosine (m ⁶ dA) residues in DNA have the potential for multiple functions within the eukaryotic genome. m⁶dA residues might recruit m⁶dA-binding proteins (left), or m⁶dA might prevent the binding of transcription factors (middle). In addition, because N ⁶ methylation of adenosines can influence Watson:Crick base pairing, m⁶dA might act by inducing local DNA denaturation (right). Any or all of these possible functional roles for m⁶dA have the potential to influence transcription or other modes of gene expression. Whether m⁶dA acts primarily by repressing or promoting gene expression remains to be determined