title: Crystal structure of ketopantoate reductase from Thermococcus kodakarensis complexed with NADP(.).
abstract: Coenzyme A (CoA) plays pivotal roles in a variety of metabolic pathways in all organisms. The biosynthetic pathway of CoA is strictly regulated by feedback inhibition. In the hyperthermophilic archaeon Thermococcus kodakarensis, ketopantoate reductase (KPR), which catalyzes the NAD(P)H-dependent reduction of 2-oxopantoate, is a target of feedback inhibition by CoA. The crystal structure of KPR from T. kodakarensis (Tk-KPR) complexed with CoA and 2-oxopantoate has previously been reported. The structure provided an explanation for the competitive inhibition mechanism. Here, further biochemical analyses of Tk-KPR and the crystal structure of Tk-KPR in complex with NADP(+) are reported. A mutational analysis implies that the residues in the binding pocket cooperatively contribute to the recognition of CoA. The structure reveals the same dimer architecture as the Tk-KPR-CoA-2-oxopantoate complex. Moreover, the positions of the residues involved in the dimer interaction are not changed by the binding of CoA and 2-oxopantoate, suggesting individual conformational changes of Tk-KPR monomers.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Aikawa
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Nishitani
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Tomita
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Atomi
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Miki
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000235:genetics; D003065:Coenzyme A / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D004795:Enzyme Stability; D009154:Mutation; D009249:NADP / Q000737:chemistry*; D011487:Protein Conformation; D019712:Thermococcus / Q000201:enzymology*
chemical_list: D009249:NADP; D000429:Alcohol Oxidoreductases; C021934:2-dehydropantoate 2-reductase; D003065:Coenzyme A
keywords: coenzyme A; competitive inhibition; feedback inhibition; hyperthermophilic archaea