Solution Conformations and Dynamics of Substrate-Bound Cytochrome P450 MycG.
Biochemistry
; 56(21): 2701-2714, 2017 05 30.
Article
en En
| MEDLINE
| ID: mdl-28488849
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 1H-15N 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 15N 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.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Bacterianas
/
Sistema Enzimático del Citocromo P-450
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Simulación de Dinámica Molecular
Idioma:
En
Revista:
Biochemistry
Año:
2017
Tipo del documento:
Article