Abstract 1534 Dissecting the Roles of Periplasmic Nitrate Reductase Structural Components and Their Impact on Molybdenum Cofactor Reactivity

The reduction of nitrate by Campylobacter jejuni is catalyzed by a periplasmic nitrate reductase (Nap) complex. The catalytic subunit, NapA, harbors a molybdenum center where catalysis takes place. The catalysis relies on the molybdenum cofactor (Moco) that has a pterin-bound molybdenum center and a partner prosthetic group, an iron-sulfur cluster. Electrons are transferred to NapA during the reduction of nitrate by a second subunit called NapB, which contains diheme cytochrome c. Once the electrons are transferred to NapA, they must reach the Mo-center following an unknown path.