2ztu

T190A mutant of D-3-hydroxybutyrate dehydrogenase complexed with NAD+

spinqualitylabelsall models 2ztu, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ztu is a 4 chain structure with sequence from Pseudomonas fragi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: MG, NAD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q5KST5_PSEFR 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 D-3-Hydroxybutyrate dehydrogenase (HBDH) from Pseudomonas fragi showed a strict stereospecificity to the d-enantiomer of 3-hydroxybutyrate (d-3-HB) as a substrate. The l-enantiomer acts as a competitive inhibitor, with a K(i) value comparable to the K(m) value for d-3-HB. We have determined the crystal structures of the ternary complex of HBDH-NAD(+)-l-3-HB and the binary complex of HBDH-NAD(+). The former structure showed a so-called closed-form conformation, which is considered an active form for catalysis, while the latter stayed mostly in a open-form conformation. The determined structures along with the site-directed mutagenesis confirmed the substrate recognition mechanism that we proposed previously. The hydrogen bonding interaction between Gln196, located in the moving helix, and the carboxyl group of the substrate/inhibitor is important for the stable ternary complex formation. Finally, the crystal structures of the Thr190 mutants, T190S and T190A, indicate that the Thr190 is a key residue for the open-closed conformational change. T190S retained 37% of the activity. In T190A, however, the activity decreased to 0.1% that of the wild-type enzyme. Fixing the position of the hydroxyl group of Thr190 to form hydrogen bonds to the pyrophosphate moiety and the carboxamide of NAD(+) seems to be a significant factor for the open-closed conformational change. Closed complex of the D-3-hydroxybutyrate dehydrogenase induced by an enantiomeric competitive inhibitor.,Nakashima K, Ito K, Nakajima Y, Yamazawa R, Miyakawa S, Yoshimoto T J Biochem. 2009 Apr;145(4):467-79. Epub 2009 Jan 3. PMID:19122202 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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