1q2x

Crystal Structure of the E243D Mutant of Aspartate Semialdehyde Dehydrogenase from Haemophilus influenzae bound with substrate aspartate semialdehyde

spinqualitylabelsall models 1q2x, resolution 2.05Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1q2x is a 2 chain structure with sequence from Haemophilus influenzae Rd KW20. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.05Å Ligands: HTI Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DHAS_HAEIN Catalyzes the NADPH-dependent formation of L-aspartate-semialdehyde (L-ASA) by the reductive dephosphorylation of L-aspartyl-4-phosphate. 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 reversible dephosphorylation of beta-aspartyl phosphate to L-aspartate-beta-semialdehyde (ASA) in the aspartate biosynthetic pathway is catalyzed by aspartate-beta-semialdehyde dehydrogenase (ASADH). The product of this reaction is a key intermediate in the biosynthesis of diaminopimelic acid, an integral component of bacterial cell walls and a metabolic precursor of lysine and also a precursor in the biosynthesis of threonine, isoleucine and methionine. The structures of selected Haemophilus influenzae ASADH mutants were determined in order to evaluate the residues that are proposed to interact with the substrates ASA or phosphate. The substrate Km values are not altered by replacement of either an active-site arginine (Arg270) with a lysine or a putative phosphate-binding group (Lys246) with an arginine. However, the interaction of phosphate with the enzyme is adversely affected by replacement of Arg103 with lysine and is significantly altered when a neutral leucine is substituted at this position. A conservative Glu243 to aspartate mutant does not alter either ASA or phosphate binding, but instead results in an eightfold increase in the Km for the coenzyme NADP. Each of the mutations is shown to cause specific subtle active-site structural alterations and each of these changes results in decreases in catalytic efficiency ranging from significant (approximately 3% native activity) to substantial (<0.1% native activity). The role of substrate-binding groups in the mechanism of aspartate-beta-semialdehyde dehydrogenase.,Blanco J, Moore RA, Faehnle CR, Coe DM, Viola RE Acta Crystallogr D Biol Crystallogr. 2004 Aug;60(Pt 8):1388-95. Epub 2004, Jul 21. PMID:15272161 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aspartate-semialdehyde dehydrogenase 3D structures

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