Methyltransferase, trithorax (IPR016569)

Short name: MeTrfase_trithorax

Overlapping homologous superfamilies


Family relationships


This entry includes a group of histone methyltransferases. The enzyme activity has been mapped to the SET domain [PMID: 12699618], originally identified in Drosophila melanogaster (Fruit fly) Su(var)3-9, E(z) and Trithorax proteins [PMID: 12039029].

The mixed lineage leukemia (MLL) gene encodes a very large nuclear protein homologous to Drosophila trithorax (Trx). MLL is required for the proper maintenance of HOX gene expression during development and hematopoiesis [PMID: 15779005]. The Trithorax group of proteins has been implicated in a variety of processes, including centromeric and telomeric silencing and cell-cycle regulation [PMID: 12447353].

The sequence conservation pattern and structural analysis of the SET domain provides clues regarding possible active site residues. There are three conserved sequence motifs in most of the SET domain, two of which had been reported earlier. The N-terminal motif (I) has characteristic glycines. The central motif (II) has a distinct pattern of polar and charged residues (Asn, His). The C-terminal motif (III) has a characteristic dyad of polar residues and the hydrophobic residue tyrosine.

GO terms

Biological Process

GO:0051568 histone H3-K4 methylation
GO:0006355 regulation of transcription, DNA-templated

Molecular Function

GO:0042800 histone methyltransferase activity (H3-K4 specific)
GO:0008270 zinc ion binding

Cellular Component

GO:0035097 histone methyltransferase complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.