| EMI domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | EMI | ||||||||
| Pfam | PF07546 | ||||||||
| InterPro | IPR011489 | ||||||||
| |||||||||
In molecular biology, the EMI domain, first named after its presence in proteins of the EMILIN family, is a small cysteine-rich protein domain of around 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, laminin-type EGF-like, collagen-like, FN3, WAP, ZP or FAS1.[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 cysteine residues, which likely form disulphide 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]
Proteins known to contain an EMI domain include:
- Vertebrate Emilins, extracellular matrix glycoproteins.
- Vertebrate Multimerins, extracellular matrix glycoproteins.
- Vertebrate Emu proteins, which could interact with several different extracellular matrix components and serve to connect and integrate the function of multiple partner molecules.
- Vertebrate beta-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.
References
- 1 2 Doliana R, Bot S, Bonaldo P, Colombatti A (November 2000). "EMI, a novel cysteine-rich domain of EMILINs and other extracellular proteins, interacts with the gC1q domains and participates in multimerization". FEBS Lett. 484 (2): 164–8. doi:10.1016/S0014-5793(00)02140-2. PMID 11068053. S2CID 38531447.
- 1 2 Callebaut I, Mignotte V, Souchet M, Mornon JP (January 2003). "EMI domains are widespread and reveal the probable orthologs of the Caenorhabditis elegans CED-1 protein". Biochem. Biophys. Res. Commun. 300 (3): 619–23. doi:10.1016/S0006-291X(02)02904-2. PMID 12507493.