title: Crystal structures of phosphite dehydrogenase provide insights into nicotinamide cofactor regeneration.
abstract: The enzyme phosphite dehydrogenase (PTDH) catalyzes the NAD(+)-dependent conversion of phosphite to phosphate and represents the first biological catalyst that has been shown to conduct the enzymatic oxidation of phosphorus. Despite investigation for more than a decade into both the mechanism of its unusual reaction and its utility in cofactor regeneration, there has been a lack of any structural data for PTDH. Here we present the cocrystal structure of an engineered thermostable variant of PTDH bound to NAD(+) (1.7 Å resolution), as well as four other cocrystal structures of thermostable PTDH and its variants with different ligands (all between 1.85 and 2.3 Å resolution). These structures provide a molecular framework for understanding prior mutational analysis and point to additional residues, located in the active site, that may contribute to the enzymatic activity of this highly unusual catalyst.
authors.affiliation: Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA.
authors.forename: Yaozhong
authors.initials: Y
authors.lastname: Zou
authors.forename: Houjin
authors.initials: H
authors.lastname: Zhang
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Brunzelle
authors.forename: Tyler W
authors.initials: TW
authors.lastname: Johannes
authors.forename: Ryan
authors.initials: R
authors.lastname: Woodyer
authors.forename: John E
authors.initials: JE
authors.lastname: Hung
authors.forename: Nikhil
authors.initials: N
authors.lastname: Nair
authors.forename: Wilfred A
authors.initials: WA
authors.lastname: van der Donk
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhao
authors.forename: Satish K
authors.initials: SK
authors.lastname: Nair
mesh_terms: D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001667:Binding, Competitive; D020134:Catalytic Domain / Q000235:genetics; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D008024:Ligands; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009243:NAD / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D015202:Protein Engineering; D044223:Pseudomonas stutzeri / Q000201:enzymology / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013447:Sulfites / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D008024:Ligands; D011994:Recombinant Proteins; D013447:Sulfites; D009243:NAD; D009247:NADH, NADPH Oxidoreductases; C429539:NAD phosphite oxidoreductase