CRYSTAL STRUCTURE OF ESCHERICHIA COLI THIOREDOXIN REDUCTASE REFINED AT 2 ANGSTROM RESOLUTION: IMPLICATIONS FOR A LARGE CONFORMATIONAL CHANGE DURING CATALYSIS
This entry represents the N-terminal domain in putative Pyridine nucleotide-disulphide oxidoreductase N-terminal domain-containing proteins and proteins that contain NADH binding domains.
Thioredoxin reductase contains FAD and NADPH binding domains that are structurally similar to the corresponding domains of the related enzyme glutathione reductase. The relative orientation of these domains is, however, very different in the two enzymes: when the FAD domains of thioredoxin and glutathione reductases are superimposed, the NADPH domain of one is rotated by 66 degrees with respect to the other. The observed binding mode of NADP+ in thioredoxin reductase is non-productive in that the nicotinamide ring is more than 17 A from the flavin ring system. Thioredoxin reductase belongs to the class-II pyridine nucleotide-disulfide oxidoreductase family.
Defined by 3 residues: CYS:A-135CYS:A-138ASP:A-139