2k3h

Structural determinants for Ca2+ and PIP2 binding by the C2A domain of rabphilin-3A

spinqualitylabelsall models 2k3h Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2k3h is a 1 chain structure with sequence from Mus musculus. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Ligands: CA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RP3A_MOUSE Protein transport. Probably involved with Ras-related protein Rab-3A in synaptic vesicle traffic and/or synaptic vesicle fusion. Could play a role in neurotransmitter release by regulating membrane flow in the nerve terminal. 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 PubMed Rabphilin-3A is a neuronal C2 domain tandem containing protein involved in vesicle trafficking. Both its C2 domains (C2A and C2B) are able to bind phosphatidylinositol 4,5-bisphosphate, a key player in the neurotransmitter release process. The rabphilin-3A C2A domain has previously been shown to bind inositol-1,4,5-trisphosphate (IP3; phosphatidylinositol 4,5-bisphosphate headgroup) in a Ca2+-dependent manner with a relatively high affinity (50 microm) in the presence of saturating concentrations of Ca2+. Moreover, IP3 and Ca2+ binding to the C2A domain mutually enhance each other. Here we present the Ca2+-bound solution structure of the C2A domain. Structural comparison with the previously published Ca2+-free crystal structure revealed that Ca2+ binding induces a conformational change of Ca2+ binding loop 3 (CBL3). Our IP3 binding studies as well as our IP3-C2A docking model show the active involvement of CBL3 in IP3 binding, suggesting that the conformational change on CBL3 upon Ca2+ binding enables the interaction with IP3 and vice versa, in line with a target-activated messenger affinity mechanism. Our data provide detailed structural insight into the functional properties of the rabphilin-3A C2A domain and reveal for the first time the structural determinants of a target-activated messenger affinity mechanism. Structural determinants for Ca2+ and phosphatidylinositol 4,5-bisphosphate binding by the C2A domain of rabphilin-3A.,Coudevylle N, Montaville P, Leonov A, Zweckstetter M, Becker S J Biol Chem. 2008 Dec 19;283(51):35918-28. Epub 2008 Oct 21. PMID:18945677 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Exophilin 3D structures Rabphilin

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