3c15 | pdb_00003c15

Complex of GS-Alpha with the Catalytic Domains of Mammalian Adenylyl Cyclase: Complex with Pyrophosphate and Mg

spinqualitylabelsall models 3c15, resolution 2.78Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3c15 is a 3 chain structure with sequence from Bos taurus, Canis lupus familiaris and Rattus norvegicus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.78Å Ligands: CL, FOK, GSP, MG, POP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ADCY5_CANLF Catalyzes the formation of the signaling molecule cAMP in response to G-protein signaling (PubMed:1618857, PubMed:8428899, PubMed:10427002, PubMed:11087399, PubMed:15591060, PubMed:16766715, PubMed:19243146). Mediates signaling downstream of ADRB1. Regulates the increase of free cytosolic Ca(2+) in response to increased blood glucose levels and contributes to the regulation of Ca(2+)-dependent insulin secretion (By similarity).[UniProtKB:O95622] Lacks catalytic activity by itself, but can associate with isoform 1 to form active adenylyl cyclase. 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 Type V and VI mammalian adenylyl cyclases (AC5, AC6) are inhibited by Ca(2+) at both sub- and supramicromolar concentration. This inhibition may provide feedback in situations where cAMP promotes opening of Ca(2+) channels, allowing fine control of cardiac contraction and rhythmicity in cardiac tissue where AC5 and AC6 predominate. Ca(2+) inhibits the soluble AC core composed of the C1 domain of AC5 (VC1) and the C2 domain of AC2 (IIC2). As observed for holo-AC5, inhibition is biphasic, showing "high-affinity" (K(i) = approximately 0.4 microM) and "low-affinity" (K(i) = approximately 100 microM) modes of inhibition. At micromolar concentration, Ca(2+) inhibition is nonexclusive with respect to pyrophosphate (PP(i)), a noncompetitive inhibitor with respect to ATP, but at >100 microM Ca(2+), inhibition appears to be exclusive with respect to PP(i). The 3.0 A resolution structure of Galphas.GTPgammaS/forskolin-activated VC1:IIC2 crystals soaked in the presence of ATPalphaS and 8 microM free Ca(2+) contains a single, loosely coordinated metal ion. ATP soaked into VC1:IIC2 crystals in the presence of 1.5 mM Ca(2+) is not cyclized, and two calcium ions are observed in the 2.9 A resolution structure of the complex. In both of the latter complexes VC1:IIC2 adopts the "open", catalytically inactive conformation characteristic of the apoenzyme, in contrast to the "closed", active conformation seen in the presence of ATP analogues and Mg(2+) or Mn(2+). Structures of the pyrophosphate (PP(i)) complex with 10 mM Mg(2+) (2.8 A) or 2 mM Ca(2+) (2.7 A) also adopt the open conformation, indicating that the closed to open transition occurs after cAMP release. In the latter complexes, Ca(2+) and Mg(2+) bind only to the high-affinity "B" metal site associated with substrate/product stabilization. Ca(2+) thus stabilizes the inactive conformation in both ATP- and PP(i)-bound states. Structural basis for inhibition of mammalian adenylyl cyclase by calcium.,Mou TC, Masada N, Cooper DM, Sprang SR Biochemistry. 2009 Apr 21;48(15):3387-97. PMID:19243146 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also 3D Adenylyl cyclase 3D structures

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