PROSITE documentation PDOC51041
EMI domain profile


The EMI domain, first named after its presence in proteins of the EMILIN family, is a small cysteine-rich module of ~75 amino acids. The EMI domain is most often found at the N-terminus of metazoan extracellular proteins that are forming or are compatible with multimer formation [1]. It is found in association with other domains, such as C1q (see <PDOC00857>), laminin-type EGF-like, collagen-like, FN3 (see <PDOC50853>), WAP (see <PDOC00026>), ZP (see <PDOC00577>) or FAS1 (see <PDOC50213>) [2]. It has been suggested that the EMI domain could be a protein-protein interaction module, as the EMI domain of EMILIN-1 was found to interact with the C1q domain of EMILIN-2 [1].

The EMI domain possesses six highly conserved cysteines residues, which likely form disulfide bonds. Other key features of the EMI domain are the C-C-x-G-[WYFH] pattern, a hydrophobic position just preceding the first cysteine (Cys1) of the domain and a cluster of hydrophobic residues between Cys3 and Cys4. The EMI domain could be made of two sub-domains, the fold of the second one sharing similarities with the C-terminal sub-module characteristic of EGF-like domains [2].

Some proteins known to contain a EMI domain are listed below:

  • Vertebrate Emilins, extracellular matrix glycoproteins.
  • Vertebrate Multimerins, extracellular matrix glycoproteins.
  • Vetebrate Emu proteins. They could interact with several different extracellular matrix components and serve to connect and integrate the function of multiple partner molecules.
  • Vertebrate β IG-H3.
  • Vertebrate osteoblast-specific factor 2 (OSF-2).
  • Mammalian NEU1/NG3 proteins.
  • Drosophila midline fasciclin.
  • Caenorhabditis elegans ced-1, a transmembrane receptor that mediates cell corpse engulfment.

The profile we developed covers the entire EMI domain.

Last update:

November 2004 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

EMI, PS51041; EMI domain profile  (MATRIX)


1AuthorsDoliana R. Bot S. Bonaldo P. Colombatti A.
TitleEMI, a novel cysteine-rich domain of EMILINs and other extracellular proteins, interacts with the gC1q domains and participates in multimerization.
SourceFEBS Lett. 484:164-168(2000).
PubMed ID11068053

2AuthorsCallebaut I. Mignotte V. Souchet M. Mornon J.-P.
TitleEMI domains are widespread and reveal the probable orthologs of the Caenorhabditis elegans CED-1 protein.
SourceBiochem. Biophys. Res. Commun. 300:619-623(2003).
PubMed ID12507493

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