CXC domain (IPR026489)

Short name: CXC_dom

Overlapping homologous superfamilies


Domain relationships


Polycomb group (Pc-G) proteins ensure the stable inheritance of expression patterns through cell division and regulate the control of cell proliferation. The Enhancer of zeste (E(z))-type of Pc-G proteins includes:

  • Drosophila melanogaster Enhancer of zeste E(z).
  • Mammalian ENX-1 and ENX-2.
  • Arabidopsis thaliana CURLY LEAF (CLF), a transcriptional repressor of floral homeotic gene AGAMOUS.
  • Arabidopsis thaliana CLF-like.
  • Arabidopsis thaliana MEDEA (MEA), a suppressor of endosperm development.
  • Arabidopsis thaliana EZA1.
These proteins contain a SET domain at the C terminus. Unique to them is the presence of a CXC domain, an ~65-residue cys-rich region preceding the SET domain. The spacing of 17 cyteines is conserved. The CXC domain contains three units of C-X(6)-C-X(3)-C-X-C motif, although the most C- terminal unit is reverse-oriented. Because of its evolutionary conservation, the CXC domain is likely to be involved in an important function of E(z)- related proteins [PMID: 8861097, PMID: 8649418, PMID: 9473645]. The CXC domain shows some similarity to the CRC domain found in the tesmin/ TSO1 protein family [PMID: 18057042].

Contributing signatures

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