1t0j
Crystal structure of a complex between voltage-gated calcium channel beta2a subunit and a peptide of the alpha1c subunit
Structural highlights
FunctionCACB2_RAT The beta subunit of voltage-dependent calcium channels contributes to the function of the calcium channel by increasing peak calcium current, shifting the voltage dependencies of activation and inactivation, modulating G protein inhibition and controlling the alpha-1 subunit membrane targeting (By similarity).[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedVoltage-gated calcium channels (Ca(V)s) govern muscle contraction, hormone and neurotransmitter release, neuronal migration, activation of calcium-dependent signalling cascades, and synaptic input integration. An essential Ca(V) intracellular protein, the beta-subunit (Ca(V)beta), binds a conserved domain (the alpha-interaction domain, AID) between transmembrane domains I and II of the pore-forming alpha(1) subunit and profoundly affects multiple channel properties such as voltage-dependent activation, inactivation rates, G-protein modulation, drug sensitivity and cell surface expression. Here, we report the high-resolution crystal structures of the Ca(V)beta2a conserved core, alone and in complex with the AID. Previous work suggested that a conserved region, the beta-interaction domain (BID), formed the AID-binding site; however, this region is largely buried in the Ca(V)beta core and is unavailable for protein-protein interactions. The structure of the AID-Ca(V)beta2a complex shows instead that Ca(V)beta2a engages the AID through an extensive, conserved hydrophobic cleft (named the alpha-binding pocket, ABP). The ABP-AID interaction positions one end of the Ca(V)beta near the intracellular end of a pore-lining segment, called IS6, that has a critical role in Ca(V) inactivation. Together, these data suggest that Ca(V)betas influence Ca(V) gating by direct modulation of IS6 movement within the channel pore. Structure of a complex between a voltage-gated calcium channel beta-subunit and an alpha-subunit domain.,Van Petegem F, Clark KA, Chatelain FC, Minor DL Jr Nature. 2004 Jun 10;429(6992):671-5. Epub 2004 May 12. PMID:15141227[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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