Involved in epigenetic gene silencing. Methylates specific cytosine residues in the retrotransposons DIRS-1 and Skipper. a 2'-deoxycytidine in DNA + S-adenosyl-L-methionine = a 5-methyl-2'-deoxycytidine in DNA + H(+) + S-adenosyl-L-homocysteine Expressed during vegetative growth and throughout development. Levels decrease after aggregation and are lowest during culmination. Mutants exhibit altered gene expression, and after undergoing 16 development cycles some mutant cells displayed reduced growth on axenic medium. DIRS-1 expression was unaffected but Skipper expression was increased in mutant cells after 16 cycles of development. Mutants lacking dmaA exhibit culmination defects including fragmented, transluscent sori, and fewer spores than wild type. Belongs to the class I-like SAM-binding methyltransferase superfamily. C5-methyltransferase family.