1vyv
|
BETA4 SUBUNIT OF CA2+ CHANNEL
OverviewOverview
High-voltage-activated Ca2+ channels are essential for diverse biological, processes. They are composed of four or five subunits, including alpha1, alpha2-delta, beta and gamma (ref. 1). Their expression and function are, critically dependent on the beta-subunit, which transports alpha1 to the, surface membrane and regulates diverse channel properties. It is believed, that the beta-subunit interacts with alpha1 primarily through the, beta-interaction domain (BID), which binds directly to the, alpha-interaction domain (AID) of alpha1; however, the molecular mechanism, of the alpha1-beta interaction is largely unclear. Here we report the, crystal structures of the conserved core region of beta3, alone and in, complex with AID, and of beta4 alone. The structures show that the, beta-subunit core contains two interacting domains: a Src homology 3 (SH3), domain and a guanylate kinase (GK) domain. The AID binds to a hydrophobic, groove in the GK domain through extensive interactions, conferring, extremely high affinity between alpha1 and beta-subunits. The BID is, essential both for the structural integrity of and for bridging the SH3, and GK domains, but it does not participate directly in binding alpha1., The presence of multiple protein-interacting modules in the beta-subunit, opens a new dimension to its function as a multi-functional protein.
About this StructureAbout this Structure
1VYV is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of the alpha1-beta subunit interaction of voltage-gated Ca2+ channels., Chen YH, Li MH, Zhang Y, He LL, Yamada Y, Fitzmaurice A, Shen Y, Zhang H, Tong L, Yang J, Nature. 2004 Jun 10;429(6992):675-80. Epub 2004 May 30. PMID:15170217
Page seeded by OCA on Wed Nov 21 05:10:18 2007