1shq

Crystal structure of shrimp alkaline phosphatase with magnesium in M3

spinqualitylabelsall models 1shq, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1shq is a 2 chain structure with sequence from Pandalus borealis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: MG, NAG, SO4, ZN Related: 1k7h, 1ew2, 1alk, 1shn Activity: Alkaline phosphatase, with EC number 3.1.3.1 Resources: FirstGlance, OCA, RCSB, PDBsum 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 Alkaline phosphatases (APs) are homodimeric metalloenzymes that catalyze the hydrolysis and transphosphorylation of phosphate monoesters. Each monomer contains a metal-binding triad that for optimal activity is usually occupied by two zinc ions and one magnesium ion. The recently determined crystal structure of cold-active shrimp alkaline phosphatase (SAP) was, however, fully occupied by zinc ions. This paper describes a metal-exchange experiment in which the zinc ion in one binding site (referred to as the M3 site) is replaced by magnesium. Crystal structures revealed a concomitant structural change: the metal exchange causes movement of a ligating histidine into a conformation in which it does not coordinate to the metal ion. The M3 site is relevant to catalysis: its occupation by magnesium is postulated to favour catalysis and it has been suggested to be a regulatory site for other APs. Further crystallographic studies show that ligand binding can induce a conformational change of an active-site arginine from a 'non-docked' (non-interacting) to a 'docked' conformation (interacting with the ligand). The first conformation has only been observed in SAP, while the latter is common in available AP structures. The observation that the arginine does not always bind the substrate may explain the increased catalytic efficiency that is generally observed for cold-active enzymes. Ligand-binding and metal-exchange crystallographic studies on shrimp alkaline phosphatase.,de Backer MM, McSweeney S, Lindley PF, Hough E Acta Crystallogr D Biol Crystallogr. 2004 Sep;60(Pt 9):1555-61. Epub 2004, Aug 26. PMID:15333925 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Alkaline phosphatase

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