3obb
Crystal structure of a possible 3-hydroxyisobutyrate Dehydrogenase from pseudomonas aeruginosa pao1Crystal structure of a possible 3-hydroxyisobutyrate Dehydrogenase from pseudomonas aeruginosa pao1
Structural highlights
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 PubMedThe beta-hydroxyacid dehydrogenases form a large family of ubiquitous enzymes that catalyze oxidation of various beta-hydroxy acid substrates to corresponding semialdehydes. Several known enzymes include beta-hydroxyisobutyrate dehydrogenase, 6-phosphogluconate dehydrogenase, 2-(hydroxymethyl)glutarate dehydrogenase, and phenylserine dehydrogenase, but the vast majority of beta-hydroxyacid dehydrogenases remain uncharacterized. Here, we demonstrate that the predicted beta-hydroxyisobutyrate dehydrogenase PA0743 from Pseudomonas aeruginosa catalyzes an NAD(+)-dependent oxidation of l-serine and methyl-l-serine but exhibits low activity against beta-hydroxyisobutyrate. Two crystal structures of PA0743 were solved at 2.2-2.3-A resolution and revealed an N-terminal Rossmann fold domain connected by a long alpha-helix to the C-terminal all-alpha domain. The PA0743 apostructure showed the presence of additional density modeled as HEPES bound in the interdomain cleft close to the predicted catalytic Lys-171, revealing the molecular details of the PA0743 substrate-binding site. The structure of the PA0743-NAD(+) complex demonstrated that the opposite side of the enzyme active site accommodates the cofactor, which is also bound near Lys-171. Site-directed mutagenesis of PA0743 emphasized the critical role of four amino acid residues in catalysis including the primary catalytic residue Lys-171. Our results provide further insight into the molecular mechanisms of substrate selectivity and activity of beta-hydroxyacid dehydrogenases. Biochemical and Structural Studies of Uncharacterized Protein PA0743 from Pseudomonas aeruginosa Revealed NAD+-dependent L-Serine Dehydrogenase.,Tchigvintsev A, Singer A, Brown G, Flick R, Evdokimova E, Tan K, Gonzalez CF, Savchenko A, Yakunin AF J Biol Chem. 2012 Jan 13;287(3):1874-83. Epub 2011 Nov 28. PMID:22128181[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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