title: X-ray structures of NADPH-dependent carbonyl reductase from Sporobolomyces salmonicolor provide insights into stereoselective reductions of carbonyl compounds.
abstract: The X-ray structures of red yeast Sporobolomyces salmonicolor carbonyl reductase (SSCR) and its complex with a coenzyme, NADPH, have been determined at a resolution of 1.8A and 1.6A, respectively. SSCR was crystallized in an orthorhombic system with the space group P2(1)2(1)2(1) and cell dimensions of a=54.86 A, b=83.49 A, and c=148.72 A. On its cocrystallization with NADPH, isomorphous crystals of the SSCR/NADPH complex were obtained. The structure of SSCR was solved by a single wavelength anomalous diffraction measurement using a selenomethionine-substituted enzyme, and that of the SSCR/NADPH complex was solved by a molecular replacement method using the solved structure of SSCR. The structures of SSCR and the SSCR/NADPH complex were refined to an R-factor of 0.193 (R(free)=0.233) and 0.211 (R(free)=0.238), respectively. SSCR has two domains, an NADPH-binding domain and a substrate-binding domain, and belongs to the short-chain dehydrogenases/reductases family. The structure of the NADPH-binding domain and the interaction between the enzyme and NADPH are very similar to those found in other structure-solved enzymes belonging to the short-chain dehydrogenases/reductases family, while the structure of the substrate-binding domain is unique. SSCR has stereoselectivity in its catalytic reaction, giving rise to excessive production of (S)-alcohols from ethyl 4-chloro-3-oxobutanoate. The X-ray structure of the SSCR/NADPH complex and preliminary modeling show that the formation of the hydrophobic channel induced by the binding of NADPH is closely related to the stereoselective reduction by SSCR.
authors.affiliation: Molecular Structure Research Group, Information Technology Center, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 791-0793, Japan. kamitori@med.kagawa-u.ac.jp
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Kamitori
authors.forename: Akihiro
authors.initials: A
authors.lastname: Iguchi
authors.forename: Akashi
authors.initials: A
authors.lastname: Ohtaki
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Yamada
authors.forename: Keiko
authors.initials: K
authors.lastname: Kita
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D000449:Aldehyde Reductase; D000074408:Aldo-Keto Reductases; D001487:Basidiomycota / Q000201:enzymology*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D008956:Models, Chemical; D008958:Models, Molecular; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D009249:NADP; D000429:Alcohol Oxidoreductases; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase