Function
DNA methyltransferase (DNMT) catalyzes the transfer of methyl group to DNA. Methylation is essential for gene expression. DNMT uses S-adenosyl methionine (SAM) as the methyl donor. The SAM analog S-adenosyl homocysteine (SAH) is a powerful inhibitor of DNMT.
- Methylguanine DNMT repairs the DNA lesion O6-methylguanine to guanine.[1]
- Methylcytosine DNMT methylates the 5 position of cytosine. [2]
- Methyladenine DNMT methylates the 6 position of adenine. [3]
- HhaI DNA methyltransferase (HDMT), a DNMT from Haemophilus haemolyticus recognizes the 5’-GCGC-3’ DNA sequence and methylates the first cytosine to convert it to 5-methylcytosine. The SAM serves as the methyl donor in the reaction and is converted to to S-adenosyl-L-homocysteine (SAH) by the reaction[4].
Relevance
DNMT inhibitors are being tested in cancer therapy.
Disease
The human ICF disorder is caused by mutations in DNMT 3B.
Structural highlights
The .
