Environmental control of the calicheamicin polyketide synthase leads to detection of a programmed octaketide and a proposal for enediyne biosynthesis

Abstract

A light in the dark: the fermentation products of the polyketide synthase CalE8 (without its cognate thioesterase) were identified and gave some insight into the elusive early steps of calicheamicin biosynthesis. Fermentation in either the light or dark resulted in different proportions of a new octaketide and led to an updated mechanistic proposal.