3v9k

Crystal structure of mouse 1-pyrroline-5-carboxylate dehydrogenase complexed with the product glutamate

spinqualitylabelsall models 3v9k, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3v9k is a 2 chain structure with sequence from Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GLU, GOL Related: 3v9g, 3v9h, 3v9i, 3v9j, 3v9l Gene: Aldh4a1 (Mus musculus) Activity: 1-pyrroline-5-carboxylate dehydrogenase, with EC number 1.5.1.12 Resources: FirstGlance, OCA, RCSB, PDBsum Function [AL4A1_MOUSE] Irreversible conversion of delta-1-pyrroline-5-carboxylate (P5C), derived either from proline or ornithine, to glutamate. This is a necessary step in the pathway interconnecting the urea and tricarboxylic acid cycles. The preferred substrate is glutamic gamma-semialdehyde, other substrates include succinic, glutaric and adipic semialdehydes (By similarity). Publication Abstract from PubMed Type II hyperprolinemia is an autosomal recessive disorder caused by a deficiency in Delta(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH; also known as ALDH4A1), the aldehyde dehydrogenase that catalyzes the oxidation of glutamate semialdehyde to glutamate. Here, we report the first structure of human P5CDH (HsP5CDH) and investigate the impact of the hyperprolinemia-associated mutation of Ser352 to Leu on the structure and catalytic properties of the enzyme. The 2. 5-A-resolution crystal structure of HsP5CDH was determined using experimental phasing. Structures of the mutant enzymes S352A (2.4 A) and S352L (2.85 A) were determined to elucidate the structural consequences of altering Ser352. Structures of the 93% identical mouse P5CDH complexed with sulfate ion (1.3 A resolution), glutamate (1.5 A), and NAD(+) (1.5 A) were determined to obtain high-resolution views of the active site. Together, the structures show that Ser352 occupies a hydrophilic pocket and is connected via water-mediated hydrogen bonds to catalytic Cys348. Mutation of Ser352 to Leu is shown to abolish catalytic activity and eliminate NAD(+) binding. Analysis of the S352A mutant shows that these functional defects are caused by the introduction of the nonpolar Leu352 side chain rather than the removal of the Ser352 hydroxyl. The S352L structure shows that the mutation induces a dramatic 8-A rearrangement of the catalytic loop. Because of this conformational change, Ser349 is not positioned to interact with the aldehyde substrate, conserved Glu447 is no longer poised to bind NAD(+), and Cys348 faces the wrong direction for nucleophilic attack. These structural alterations render the enzyme inactive. The Three-Dimensional Structural Basis of Type II Hyperprolinemia.,Srivastava D, Singh RK, Moxley MA, Henzl MT, Becker DF, Tanner JJ J Mol Biol. 2012 Apr 16. PMID:22516612 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Pyrroline-5-carboxylate dehydrogenase

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