EMSY is a protein that interacts with the exon 3-encoded transcriptional activation domain of breast cancer susceptibility gene 2 (BRCA2) and has been implicated in BRCA2-associated sporadic breast and ovarian cancer. Structural domains comprising this superfamily share the structure of its N-terminal ENT domain. This domain also found in many plant proteins which also comprise chromatin-remodelling domains which suggest that EMSY may have a role in chromatin-related processes. Further evidence is provided by the fact that several chromatin-regulator proteins, including HP1beta and BS69, bind directly to EMSY via a conserved motif adjacent to the ENT domain. The ENT domain forms a homodimer by the antiparallel packing of the long amino-terminal alpha-helix from each subunit and is stabilized mainly by hydrophobic residues at the dimer interface. This EMSY dimerization provides two potential interaction sites for HP1 and other proteins adding even more complexity to the protein interaction network that coordinates chromatin remodelling PMID:15947784,PMID:16615912.