InterPro domain: IPR005491

The EMSY N-terminal (ENT) domain is a ~90-residue module, which is unique in the human proteome, although multiple copies are found in Arabidopsis proteins. In the plant proteins, the ENT domains are accompanied by Agenet domains, plant specific homologues of Tudor domains [ 1 , 2 ].

The ENT domain consists of a unique arrangement of five alpha-helices that fold into a helical bundle arrangement. Overall, the three-dimensional structure adopts a club-like shape that consists of an extended N-terminal alpha-helix that connects to a helical bundle substructure. The ENT domain forms a homodimer via the anti-parallel packing of the long N-terminal alpha-helix from each subunit [ 3 , 4 ].

1. EMSY links the BRCA2 pathway to sporadic breast and ovarian cancer. Cell 115, 523-35
2. The Tudor domain 'Royal Family': Tudor, plant Agenet, Chromo, PWWP and MBT domains. Trends Biochem. Sci. 28, 69-74
3. Crystal structure of the ENT domain of human EMSY. J. Mol. Biol. 350, 964-73
4. Binding of EMSY to HP1beta: implications for recruitment of HP1beta and BS69. EMBO Rep. 6, 675-80