Catalytic mechanism and molecular engineering of quinolone biosynthesis in dioxygenase AsqJ.
Nat Commun
; 9(1): 1168, 2018 03 21.
Article
in En
| MEDLINE
| ID: mdl-29563492
ABSTRACT
The recently discovered FeII/α-ketoglutarate-dependent dioxygenase AsqJ from Aspergillus nidulans stereoselectively catalyzes a multistep synthesis of quinolone alkaloids, natural products with significant biomedical applications. To probe molecular mechanisms of this elusive catalytic process, we combine here multi-scale quantum and classical molecular simulations with X-ray crystallography, and in vitro biochemical activity studies. We discover that methylation of the substrate is essential for the activity of AsqJ, establishing molecular strain that fine-tunes π-stacking interactions within the active site. To rationally engineer AsqJ for modified substrates, we amplify dispersive interactions within the active site. We demonstrate that the engineered enzyme has a drastically enhanced catalytic activity for non-methylated surrogates, confirming our computational data and resolved high-resolution X-ray structures at 1.55 Å resolution. Our combined findings provide crucial mechanistic understanding of the function of AsqJ and showcase how combination of computational and experimental data enables to rationally engineer enzymes.
Full text:
1
Database:
MEDLINE
Main subject:
Aspergillus nidulans
/
Fungal Proteins
/
Quinolones
/
Alkaloids
/
Alpha-Ketoglutarate-Dependent Dioxygenase FTO
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2018
Type:
Article
Affiliation country:
Germany