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DNA (cytosine-5)-methyltransferase 3B (DNA methyltransferase-3B) or DNA methyltransferase HsaIIIB

Function: - responsible for genome wide de novo methylation in mammals - essential for the establishment of DNA methylation patterns during development - may preferentially methylate nucleosomal DNA within the nucleosome core region - may function as transcriptional co-repressor by associating with CBX4 - seems to be involved in gene silencing - involved in activation of BAG1 gene expression by modulating dimethylation of promoter histone H3 at H3K4 & H3K9 (DNMT1 & CTCFL/BORIS may be involved) - isoforms 4 & 5 are probably not functional due to the deletion of two conserved methyltransferase motifs - activated by binding to the regulatory factor DNMT3L (putative) - sumoylated - interacts with BAZ2A/TIP5, SUV39H1 & CBX4 - interacts with SETDB1, UBL1 & UBE2I9 - interacts with DNMT1 & DNMT3A - interacts with the PRC2/EED-EZH2 complex S-adenosyl-L-methionine + DNA = S-adenosyl-L-homocysteine + DNA containing 5-methylcytosine Structure: - the PWWP domain is essential for targeting to pericentric heterochromatin - belongs to the C5-methyltransferase family - contains 1 ADD-type Zn+2 finger - contains 1 PWWP domain Compartment: nucleus Alternative splicing: named isoforms=6 Expression: - ubiquitous - highly expressed in fetal liver, heart, kidney, placenta - lower levels in spleen, colon, brain, liver, small intestine, lung, peripheral blood mononuclear cells, & skeletal muscle - isoform 1 is expressed in all tissues except brain, skeletal muscle & PBMC - isoform 3 is ubiquitous - isoform 4 is expressed in all tissues except brain, skeletal muscle, lung & prostate - isoform 5 is detectable in testis & at very low level in brain & prostate Pathology: - defects associated with immunodeficiency centromeric instability-facial anomalies (ICF) syndrome.

General

DNA (cytosine-5)-methyltransferase

Properties

SIZE: entity length = 853 aa MW = 96 kD COMPARTMENT: cell nucleus MOTIF: DNMT1,DNMT3A interaction {1-298} MOTIF: PWWP domain {225-283} Zinc finger NAME: Zinc finger SITE: 435-527 EFFECTOR-BOUND: Zn+2 MOTIF: PRC2/EED-EZH2 interaction {435-527} cysteine residue {C651}

Database Correlations

OMIM correlations MORBIDMAP 602900 UniProt Q9UBC3 PFAM correlations Entrez Gene 1789 Kegg hsa:1789 ENZYME 2.1.1.37

References

  1. UniProt :accession Q9UBC3
  2. DNMT3Bbase; Note: DNMT3B mutation db http://bioinf.uta.fi/DNMT3Bbase/

Component-of

nucleolar remodeling complex (NoRC complex)