Download MendeleySolution Conformations and Dynamics of Substrate-Bound Cytochrome P450 MycG.
Tietz, D.R., Podust, L.M., Sherman, D.H., Pochapsky, T.C.(2017) Biochemistry 56: 2701-2714
- PubMed: 28488849
- DOI: https://doi.org/10.1021/acs.biochem.7b00291
- Primary Citation of Related Structures:
5UHU - PubMed Abstract:
MycG is a P450 monooxygenase that catalyzes the sequential hydroxylation and epoxidation of mycinamicin IV (M-IV), the last two steps in the biosynthesis of mycinamicin II, a macrolide antibiotic isolated from Micromonospora griseorubida. The crystal structure of MycG with M-IV bound was previously determined but showed the bound substrate in an orientation that did not rationalize the observed regiochemistry of M-IV hydroxylation. Nuclear magnetic resonance paramagnetic relaxation enhancements provided evidence of an orientation of M-IV in the MycG active site more compatible with the observed chemistry, but substrate-induced changes in the enzyme structure were not characterized. We now describe the use of amide 1 H- 15 N residual dipolar couplings as experimental restraints in solvated "soft annealing" molecular dynamics simulations to generate solution structural ensembles of M-IV-bound MycG. Chemical shift perturbations, hydrogen-deuterium exchange, and 15 N relaxation behavior provide insight into the dynamic and electronic perturbations in the MycG structure in response to M-IV binding. The solution and crystallographic structures are compared, and the possibility that the crystallographic orientation of bound M-IV represents an inhibitory mode is discussed.
Organizational Affiliation:
Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California , San Diego, California 92093, United States.
