NADH binding site and catalysis of NADH peroxidase.
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.
Stehle
T
T
Institut für Organische Chemie und Biochemie der Universität, Freiburg im Breisgau, Federal Republic of Germany.
Claiborne
A
A
Schulz
G E
GE
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
D009243:NAD; D005182:Flavin-Adenine Dinucleotide; D006861:Hydrogen Peroxide; D010544:Peroxidases; C021845:NAD+ peroxidase; D003545:Cysteine