Diiron Monooxygenase Complex Involved in Antimycin Biosynthesis Transforms Anthraniloyl Thioester into 3-Aminosalicyl Thioester on a Carrier Protein

Antimycins feature a nine-membered dilactone core and a bioactivity-essential 3-formaminosalic acid. Herein, we demonstrate that the formation of 3-aminosalicylate is catalyzed by AntHIJKL, a multicomponent diiron monooxygenase complex, via an unusual carrier protein-dependent oxidative rearrangement. AntH and AntJ constitute the minimal catalytic unit to convert anthraniloyl thioester into 3-aminosalicyl thioester on the carrier protein AntG, while AntI, AntK, and AntL function as auxiliary redox partners. This study expands the functional scope of multicomponent diiron monooxygenases.