ADDz domain found in DNA (cytosine-5) methyltransferases (C5-MTases) 3b (Dnmt3b)
ADDz_Dnmt3b is an active catalytic domain of Dnmt3b. Dnmt3b is a member of the Dnmt3 family and is a de novo DNA methyltransferases that has an N-terminal variable region followed by a conserved PWWP region and the cysteine-rich ADDz domain. DNA methylation is an important epigenetic mechanism involved in diverse biological processes such as embryonic development, gene expression, and genomic imprinting. The methyltransferase activity of Dnmt3a is not only responsible for the establishment of DNA methylation pattern, but is also essential for the inheritance of these patterns during mitosis. Dnmt3b is ubiquitously expressed in most adult tissues. The ADDz_Dnmt3 domain is a PHD-like zinc finger motif that contains two parts, a C2-C2 and a PHD-like zinc finger. PHD zinc finger domains have been identified in more than 40 proteins that are mainly involved in chromatin mediated transcriptional control; the classical PHD zinc finger has a C4-H-C3 motif that spans about 50-80 amino acids. In ADDz, the conserved histidine residue of the PHD finger is replaced by a cysteine, and an additional zinc finger C2-C2 like motif is located about twenty residues upstream of the C4-C-C3 motif. A knockout of Dnmt3b has been shown to be lethal in the mouse model.
Jiyao W et al.(2023). "The conserved domain database in 2023.",