Specifically methylates cytosine 38 in the anticodon loop of tRNA(Asp) (By similarity). Also has DNA (cytosine-5)-methyltransferase activity (PubMed:23103599). Shows affinity for both tRNA(Asp) and DNA substrates (PubMed:23103599). cytidine(38) in tRNA + S-adenosyl-L-methionine = 5-methylcytidine(38) in tRNA + H(+) + S-adenosyl-L-homocysteine a 2'-deoxycytidine in DNA + S-adenosyl-L-methionine = a 5-methyl-2'-deoxycytidine in DNA + H(+) + S-adenosyl-L-homocysteine Belongs to the class I-like SAM-binding methyltransferase superfamily. C5-methyltransferase family.