Dnmt3L is a nuclear protein with similarity to DNA methyltransferases, but is not thought to function as a DNA methyltransferase as it does not contain the amino acid residues necessary for methyltransferase activity. Dnmt3L is 387 amino acids in length and contains an ADD-type zinc finger, plays a crucial role in the regulation of gene expression through involvement in DNA methylation processes. Although Dnmt3L lacks intrinsic DNA methyltransferase activity, Dnmt3L remains essential for stimulating de novo methylation by other Dnmt family members, particularly Dnmt3a and Dnmt3b, thereby influencing genomic imprinting and epigenetic regulation. Notably, Dnmt3L interacts with histone deacetylase 1 (HDAC1), which enhances transcriptional repression capabilities, further underscoring significance in epigenetic modifications.