Skatole is a pungent heterocyclic compound derived from the essential amino acid l-tryptophan by bacteria in the mammalian digestive tract. The four-step anaerobic conversion of tryptophan to skatole is well-established
though, to date, no aerobic counterpart has been reported. Herein, we report the discovery of the oxygen-dependent skatole synthase SktA that single-handedly converts 5-bromo-l-tryptophan to 5-bromoskatole, obviating the need for a multienzyme process. SktA is part of a three-gene biosynthetic gene cluster (BGC) in the cyanobacterium