SETMAR Recombinant Protein

This gene encodes a fusion protein that contains an N-terminal histone-lysine N-methyltransferase domain and a C-terminal mariner transposase domain. The encoded protein binds DNA and functions in DNA repair activities including non-homologous end joining and double strand break repair. The SET domain portion of this protein specifically methylates histone H3 lysines 4 and 36. This gene exists as a fusion gene only in anthropoid primates, other organisms lack mariner transposase domain. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jan 2013]

Function: Histone methyltransferase that methylates 'Lys-4' and 'Lys-36' of histone H3, 2 specific tags for epigenetic transcriptional activation. Specifically mediates dimethylation of H3 'Lys-36'. Has sequence-specific DNA-binding activity and recognizes the 19-mer core of the 5'-terminal inverted repeats (TIRs) of the Hsmar1 element. Has DNA nicking activity. Has in vivo end joining activity and may mediate genomic integration of foreign DNA. Ref.1 Ref.5 Ref.7 Ref.8

Catalytic activity: S-adenosyl-L-methionine + L-lysine-[histone] = S-adenosyl-L-homocysteine + N(6)-methyl-L-lysine-[histone].

Cofactor: Binds 1 magnesium ion per subunit.

Subcellular location: Nucleus

Probable. Chromosome

Probable.

Tissue specificity: Widely expressed, with highest expression in placenta and ovary and lowest expression in skeletal muscle. Ref.1

Domain: The mariner transposase Hsmar1 region mediates DNA-binding. It has no transposase activity because the active site contains an Asn in position 610 instead of a Asp residue.

Miscellaneous: The mariner transposase region in only present in primates and appeared 40-58 million years ago, after the insertion of a transposon downstream of a preexisting SET gene, followed by the de novo exonization of previously non-coding sequence and the creation of a new intron.

Sequence similarities: In the N-terminal section; belongs to the class V-like SAM-binding methyltransferase superfamily.In the C-terminal section; belongs to the mariner transposase family.Contains 1 post-SET domain.Contains 1 pre-SET domain.Contains 1 SET domain.