DNA (cytosine-5-)-methyltransferase activity, acting on CpG substrates

Definition

Target type: molecularfunction

Catalysis of the reaction: S-adenosyl-L-methionine + CpG (in DNA) = S-adenosyl-L-homocysteine + 5-MeCpG (in DNA). [EC:2.1.1.37, PMID:15689527]

DNA (cytosine-5-)-methyltransferases (DNMTs) are a family of enzymes that catalyze the transfer of a methyl group from a donor molecule, typically S-adenosyl methionine (SAM), to the 5' position of cytosine bases in DNA. This process, known as DNA methylation, is a crucial epigenetic modification that plays a vital role in regulating gene expression, genomic imprinting, and maintaining genomic stability. DNMTs exhibit specificity for CpG dinucleotides, which are cytosine bases followed by a guanine base. This specificity arises from the enzyme's structure, which contains a conserved catalytic domain that interacts with both the cytosine base and the adjacent guanine base. The catalytic mechanism of DNMTs involves a series of steps, including: 1) Binding of SAM to the enzyme, 2) Recognition and binding of the CpG dinucleotide within the DNA substrate, 3) Transfer of the methyl group from SAM to the 5' position of cytosine, 4) Release of the methylated DNA and S-adenosyl homocysteine (SAH) byproduct. DNMTs are essential for development and cellular function. In mammals, there are three main DNMTs: DNMT1, DNMT3A, and DNMT3B. DNMT1 is considered a "maintenance" methyltransferase, as it primarily copies existing methylation patterns to newly synthesized DNA strands during replication. DNMT3A and DNMT3B establish de novo methylation patterns during development and play a role in regulating gene expression. Dysregulation of DNMT activity has been implicated in various diseases, including cancer, autoimmune disorders, and developmental disorders.'
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Proteins (2)

Compounds (10)