Dnmt3a showed higher DNA methylation activity than Dnmt3b towards naked DNA and the naked part of nucleosomal DNA. On the other hand, Dnmt3a scarcely methylated the DNA within the nucleosome core region, while Dnmt3b significantly did, although the activity was low.

Normal Function The DNMT3A gene provides instructions for making an enzyme called DNA methyltransferase 3 alpha. This enzyme is involved in DNA methylation, which is the addition of methyl groups, consisting of one carbon atom and three hydrogen atoms, to DNA molecules.

DNA (cytosine-5)-methyltransferase 1 is an enzyme that catalyzes the transfer of methyl groups to specific CpG structures in DNA, a process called DNA methylation. In humans, it is encoded by the DNMT1 gene….

Gene. DNMT3A is a 130 kDa protein encoded by 23 exons found on chromosome 2p23 in humans.

DNA (cytosine-5-)-methyltransferase 3 beta, is an enzyme that in humans in encoded by the DNMT3B gene. Mutation in this gene are associated with immunodeficiency, centromere instability and facial anomalies syndrome.

Mammalian DNA methylation patterns are mainly generated by two de novo DNA methyltransferases, DNMT3A and DNMT3B 5. The catalytically inactive DNMT3-like protein (DNMT3L) has an important regulatory role in this process by acting as cofactor of DNMT3A or DNMT3B 6, 7, 8.

“Dnmt3b, de novo DNA methyltransferase, interacts with SUMO-1 and Ubc9 through its N-terminal region and is subject to modification by SUMO-1”. Biochemical and Biophysical Research Communications. 289 (4): 862–8. doi: 10.1006/bbrc.2001.6057.

Deficiency of DNA methyltransferase 3B in the ICF syndrome leads to hypomethylation of satellites 2 and 3 in pericentric heterochromatin. This hypomethylation is associated with centromeric decondensation and chromosomal rearrangements, suggesting that these satellite repeats have an important structural role.