title: NADH binding site and catalysis of NADH peroxidase.
abstract: The structure of the complex between cofactor NADH and the enzyme NADH peroxidase from Streptococcus faecalis 10C1 (Enterococcus faecalis) has been determined by crystal soaking, X-ray data collection, model building of NADH and refinement at 0.24-nm resolution based on the known enzyme structure [Stehle, T., Ahmed, S. A., Claiborne, A. & Schulz, G. E. (1991) J. Mol. Biol. 221, 1325-1344]. Apart from NADH, the catalytic center of the enzyme contains FAD and a cysteine that shuttles between thiolate and sulfenic acid states. Unfortunately, this cysteine was irreversibly oxidized to a cysteine sulfonic acid in the established enzyme structure. Based on the geometry of the catalytic center, we discuss the stabilization of the oxidation-sensitive sulfenic acid and propose a reaction mechanism.
authors.affiliation: Institut für Organische Chemie und Biochemie der Universität, Freiburg im Breisgau, Federal Republic of Germany.
authors.forename: T
authors.initials: T
authors.lastname: Stehle
authors.forename: A
authors.initials: A
authors.lastname: Claiborne
authors.forename: G E
authors.initials: GE
authors.lastname: Schulz
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D003461:Crystallography; D003545:Cysteine / Q000378:metabolism; D013293:Enterococcus faecalis / Q000201:enzymology*; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D008958:Models, Molecular; D009243:NAD / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism* / Q000648:ultrastructure; D017434:Protein Structure, Tertiary; D014961:X-Ray Diffraction
chemical_list: D009243:NAD; D005182:Flavin-Adenine Dinucleotide; D006861:Hydrogen Peroxide; D010544:Peroxidases; C021845:NAD+ peroxidase; D003545:Cysteine