1o0s

Crystal Structure of Ascaris suum Malic Enzyme Complexed with NADH

spinqualitylabelsall models 1o0s, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1o0s is a 2 chain structure with sequence from Ascaris suum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: NAI, TTN Related: 1llq Activity: Malate dehydrogenase (oxaloacetate-decarboxylating), with EC number 1.1.1.38 Resources: FirstGlance, OCA, PDBe, 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 The crystal structure of the mitochondrial NAD-malic enzyme from Ascaris suum, in a quaternary complex with NADH, tartronate, and magnesium has been determined to 2.0-A resolution. The structure closely resembles the previously determined structure of the same enzyme in binary complex with NAD. However, a significant difference is observed within the coenzyme-binding pocket of the active site with the nicotinamide ring of NADH molecule rotating by 198 degrees over the C-1-N-1 bond into the active site without causing significant movement of the other catalytic residues. The implications of this conformational change in the nicotinamide ring to the catalytic mechanism are discussed. The structure also reveals a binding pocket for the divalent metal ion in the active site and a binding site for tartronate located in a highly positively charged environment within the subunit interface that is distinct from the active site. The tartronate binding site, presumably an allosteric site for the activator fumarate, shows striking similarities and differences with the activator site of the human NAD-malic enzyme that has been reported recently. Thus, the structure provides additional insights into the catalytic as well as the allosteric mechanisms of the enzyme. Crystallographic studies on Ascaris suum NAD-malic enzyme bound to reduced cofactor and identification of an effector site.,Rao GS, Coleman DE, Karsten WE, Cook PF, Harris BG J Biol Chem. 2003 Sep 26;278(39):38051-8. Epub 2003 Jul 9. PMID:12853453 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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