1cip

GI-ALPHA-1 SUBUNIT OF GUANINE NUCLEOTIDE-BINDING PROTEIN COMPLEXED WITH A GTP ANALOGUE

spinqualitylabelsall models 1cip, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1cip is a 1 chain structure with sequence from Rattus norvegicus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: GNP, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GNAI1_RAT Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G(i) proteins are involved in hormonal regulation of adenylate cyclase: they inhibit the cyclase in response to beta-adrenergic stimuli. The inactive GDP-bound form prevents the association of RGS14 with centrosomes and is required for the translocation of RGS14 from the cytoplasm to the plasma membrane. May play a role in cell division. 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 The structure of the G protein Gialpha1 complexed with the nonhydrolyzable GTP analog guanosine-5'-(betagamma-imino)triphosphate (GppNHp) has been determined at a resolution of 1.5 A. In the active site of Gialpha1. GppNHp, a water molecule is hydrogen bonded to the side chain of Glu43 and to an oxygen atom of the gamma-phosphate group. The side chain of the essential catalytic residue Gln204 assumes a conformation which is distinctly different from that observed in complexes with either guanosine 5'-O-3-thiotriphosphate or the transition state analog GDP.AlF4-. Hydrogen bonding and steric interactions position Gln204 such that it interacts with a presumptive nucleophilic water molecule, but cannot interact with the pentacoordinate transition state. Gln204 must be released from this auto-inhibited state to participate in catalysis. RGS proteins may accelerate the rate of GTP hydrolysis by G protein alpha subunits, in part, by inserting an amino acid side chain into the site occupied by Gln204, thereby destabilizing the auto-inhibited state of Galpha. Structure of Gialpha1.GppNHp, autoinhibition in a galpha protein-substrate complex.,Coleman DE, Sprang SR J Biol Chem. 1999 Jun 11;274(24):16669-72. PMID:10358003 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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