3f6y

Conformational Closure of the Catalytic Site of Human CD38 Induced by Calcium

spinqualitylabelsall models 3f6y, resolution 1.45Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3f6y is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.45Å Ligands: CA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CD38_HUMAN Synthesizes cyclic ADP-ribose, a second messenger for glucose-induced insulin secretion. Also has cADPr hydrolase activity. Also moonlights as a receptor in cells of the immune system. 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 First identified on the surface of lymphoids as a type II transmembrane protein, CD38 has now been established to have dual functions not only as a receptor but also as a multifunctional enzyme,catalyzing the synthesis of and hydrolysis of a general calcium messenger molecule, cyclic ADP-ribose(cADPR). The receptorial functions of CD38 include the induction of cell adhesion, differentiation,apoptosis, and cytokine production upon antibody ligation. Here we determined the crystal structure of calcium-loaded human CD38 at 1.45 A resolution which reveals that CD38 undergoes dramatic structural changes to an inhibited conformation in the presence of calcium. The structural changes are highly localized and occur in only two regions. The first region is part of the active site and consists of residues 121-141.In the presence of calcium, W125 moves 5 A into the active site and forms hydrophobic interactions with W189. The movement closes the active site pocket and reduces entry of substrates, resulting in inhibition of the enzymatic activity. The structural role of calcium in inducing these conformational changes is readily visualized in the crystal structure. The other region that undergoes calcium-induced changes is at the receptor region, where a highly ordered helix is unraveled to a random coil. The results suggest a novel conformational coupling mechanism, whereby protein interaction targeted at the receptor region can effectively regulate the enzymatic activity of CD38. Conformational Closure of the Catalytic Site of Human CD38 Induced by Calcium.,Liu Q, Graeff R, Kriksunov IA, Lam CM, Lee HC, Hao Q Biochemistry. 2008 Dec 30;47(52):13966-73. PMID:19117080 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cluster of Differentiation CD38

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