1wmb

[[Image:1wmb.gif|left|200px]]<br /><applet load="1wmb" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1wmb, resolution 2.0&Aring;" />

'''Crystal structure of NAD dependent D-3-hydroxybutylate dehydrogenase'''<br />

==Overview==

The gene coding for d-3-hydroxybutyrate dehydrogenase (HBDH) was cloned from Pseudomonas fragi. The nucleotide sequence contained a 780 bp open reading frame encoding a 260 amino acid residue protein. The recombinant enzyme was efficiently expressed in Escherichia coli cells harboring pHBDH11 and was purified to homogeneity as judged by SDS-PAGE. The enzyme showed a strict stereospecificity to the D-enantiomer (3R-configuration) of 3-hydroxybutyrate as a substrate. Crystals of the ligand-free HBDH and of the enzyme-NAD+ complex were obtained using the hanging-drop, vapor-diffusion method. The crystal structure of the HBDH was solved by the multiwavelength anomalous diffraction method using the SeMet-substituted enzyme and was refined to 2.0 A resolution. The overall structure of P.fragi HBDH, including the catalytic tetrad of Asn114, Ser142, Tyr155, and Lys159, shows obvious relationships with other members of the short-chain dehydrogenase/reductase (SDR) family. A cacodylate anion was observed in both the ligand-free enzyme and the enzyme-NAD+ complex, and was located near the catalytic tetrad. It was shown that the cacodylate inhibited the NAD+-dependent D-3-hydroxybutyrate dehydrogenation competitively, with a Ki value of 5.6 mM. From the interactions between cacodylate and the enzyme, it is predicted that substrate specificity is achieved through the recognition of the 3-methyl and carboxyl groups of the substrate.

 

==About this Structure==

1WMB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_fragi Pseudomonas fragi] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=CAC:'>CAC</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-hydroxybutyrate_dehydrogenase 3-hydroxybutyrate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.30 1.1.1.30] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WMB OCA].

 

==Reference==

D-3-hydroxybutyrate dehydrogenase from Pseudomonas fragi: molecular cloning of the enzyme gene and crystal structure of the enzyme., Ito K, Nakajima Y, Ichihara E, Ogawa K, Katayama N, Nakashima K, Yoshimoto T, J Mol Biol. 2006 Jan 27;355(4):722-33. Epub 2005 Nov 14. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16325199 16325199]

[[Category: 3-hydroxybutyrate dehydrogenase]]

[[Category: Ichihara, E.]]

[[Category: Ito, K.]]

[[Category: Nakajima, Y.]]

[[Category: Ogawa, K.]]

[[Category: Yoshimoto, T.]]