My watch list

Sema domain


Sema domain, immunoglobulin domain (Ig), short basic domain

Identifiers
Symbol	Sema
Pfam	PF01403
InterPro	IPR001627
SCOP	1olz
Available PDB structures: 1shyB:55-500 1ux3A:55-500 1olzA:50-482 1q47A:57-498

The Sema domain is a structural domain of semaphorins, which are a large family of secreted and transmembrane proteins, some of which function as repellent signals during axon guidance. Sema domains also occur in UniProt P08581 the hepatocyte growth factor receptor and UniProt P51805 ^[1] and in viral proteins.

Additional recommended knowledge

Weighing the right way

Essential Laboratory Skills Guide

Daily Visual Balance Check

CD100 (also called SEMA4D) is associated with PTPase and serine kinase activity. CD100 increases PMA, CD3 and CD2 induced T cell proliferation, increases CD45 induced T cell adhesion, induces B cell homotypic adhesion and down-regulates B cell expression of CD23.

The Sema domain is characterised by a conserved set of cysteine residues, which form four disulphide bonds to stabilise the structure. The Sema domain fold is a variation of the beta propeller topology, with seven blades radially arranged around a central axis. Each blade contains a four- stranded (strands A to D) antiparallel beta sheet. The inner strand of each blade (A) lines the channel at the centre of the propeller, with strands B and C of the same repeat radiating outward, and strand D of the next repeat forming the outer edge of the blade. The large size of the Sema domain is not due to a single inserted domain but results from the presence of additionnal secondary structure elements inserted in most of the blades. The Sema domain uses a 'loop and hook' system to close the circle between the first and the last blades. The blades are constructed sequentially with an N-terminal beta- strand closing the circle by providing the outermost strand (D) of the seventh (C-terminal) blade. The beta-propeller is further stabilized by an extension of the N-terminus, providing an additional, fifth beta-strand on the outer edge of blade 6^[2]^[3]^[4].

CD molecules are leucocyte antigens on cell surfaces. CD antigens nomenclature is updated at Protein Reviews On The Web (http://mpr.nci.nih.gov/prow/).

Human proteins containing this domain

MET; MST1R; PLXNA1; PLXNA2; PLXNA3; PLXNA4; PLXNB1; PLXNB2; PLXNB3; PLXND1; SEMA3A; SEMA3B; SEMA3C; SEMA3D; SEMA3E; SEMA3F; SEMA3G; SEMA4A; SEMA4B; SEMA4C; SEMA4D; SEMA4F; SEMA4G; SEMA5A; SEMA5B; SEMA6A; SEMA6B; SEMA6C; SEMA6D; SEMA7A;

References

^ Goodman CS, Winberg ML, Noordermeer JN, Tamagnone L, Comoglio PM, Spriggs MK, Tessier-Lavigne M (1998). "Plexin A is a neuronal semaphorin receptor that controls axon guidance". Cell 95 (7): 903-916. PMID 9875845.
^ Nikolov DB, Himanen JP, Rajashankar KR, Lu M, Antipenko A, Lesniak J, Barton WA, Hoemme C, Puschel AW, van Leyen K, Nardi-Dei V (2003). "Structure of the semaphorin-3A receptor binding module". Neuron 39 (4): 589-598. PMID 12925274.
^ Stuart DI, Jones EY, Harlos K, Esnouf RM, Davis SJ, Love CA, Mavaddat N (2003). "The ligand-binding face of the semaphorins revealed by the high-resolution crystal structure of SEMA4D". Nat. Struct. Biol. 10 (10): 843-848. PMID 12958590.
^ Lazarus RA, Kirchhofer D, Stamos J, Yao X, Wiesmann C (2004). "Crystal structure of the HGF beta-chain in complex with the Sema domain of the Met receptor". EMBO J. 23 (12): 2325-2335. PMID 15167892.

This article includes text from the public domain Pfam and InterPro IPR001627

Categories: Protein domains | Protein families | Single-pass transmembrane proteins

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Sema_domain". A list of authors is available in Wikipedia.