Enzymatic synthesis of azide by a promiscuous N-nitrosylase

Azides are energy-rich compounds with diverse representation in a broad range of scientific disciplines, including material science, synthetic chemistry, pharmaceutical science and chemical biology. Despite ubiquitous usage of the azido group, the underlying biosynthetic pathways for its formation remain largely unknown. Here we report the characterization of an enzymatic route for de novo azide construction. We demonstrate that Tri17, a promiscuous ATP- and nitrite-dependent enzyme, catalyses organic azide synthesis through sequential N-nitrosation and dehydration of aryl hydrazines. Through biochemical, structural and computational analyses, we further propose a plausible molecular mechanism for azide synthesis that sets the stage for future biocatalytic applications and biosynthetic pathway engineering. Despite widespread use of azides across material science and various areas across chemistry, the underlying biosynthetic pathways for its formation have so far been unknown. Now, a promiscuous ATP-utilizing enzyme, Tri17, capable of synthesizing various azide molecules has been identified. Biochemical, structural and computational analyses support a potential molecular mechanism for azide formation by Tri17.