The enzyme pseudooxynicotine amine oxidase from Pseudomonas putida S16 is not an oxidase, but a dehydrogenase
Vishakha Choudhary, Kevin Wu, Zhiyao Zhang, Mark Dulchavsky, Todd J. Barkman, James C.A. Bardwell, Frederick Stull
Abstract
, but can be rapidly oxidized by CycN, indicating that Pnao indeed acts as a dehydrogenase that uses CycN as its oxidant. Comparing steady-state kinetics with transient kinetic experiments revealed that product release primarily limits turnover by Pnao. We also resolved the crystal structure of Pnao at 2.60 Å, which shows that Pnao has a similar structural fold as NicA2. Furthermore, rigid-body docking of the structure of CycN with Pnao and NicA2 identified a potential conserved binding site for CycN on these two enzymes. Taken together, our results demonstrate that although Pnao and NicA2 show a high degree of similarity to flavin containing amine oxidases that use dioxygen directly, both enzymes are actually dehydrogenases.