Catalytic mechanism and molecular engineering of quinolone biosynthesis in dioxygenase AsqJ

Sophie L. Mader, Alois Bräuer, Michael Groll, Ville R.I. Kaila

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


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.

Original languageEnglish
Article number1168
JournalNature Communications
Issue number1
StatePublished - 1 Dec 2018


Dive into the research topics of 'Catalytic mechanism and molecular engineering of quinolone biosynthesis in dioxygenase AsqJ'. Together they form a unique fingerprint.

Cite this