Crotonylation of key metabolic enzymes regulates carbon catabolite repression in Streptomyces roseosporus.

Due to the plethora natural products made by Streptomyces, the regulation of its metabolism are of great interest, whereas there is a lack of detailed understanding of the role of posttranslational modifications (PTM) beyond traditional transcriptional regulation. Herein with Streptomyces roseosporus as a model, we showed that crotonylation is widespread on key enzymes for various metabolic pathways, and sufficient crotonylation in primary metabolism and timely elimination in secondary metabolism are required for proper Streptomyces metabolism. Particularly, the glucose kinase Glk, a keyplayer of carbon catabolite repression (CCR) regulating bacterial metabolism, is identified reversibly crotonylated by the decrotonylase CobB and the crotonyl-transferase Kct1 to negatively control its activity. Furthermore, crotonylation positively regulates CCR for Streptomyces metabolism through modulation of the ratio of glucose uptake/Glk activity and utilization of carbon sources. Thus, our results revealed a regulatory mechanism that crotonylation globally regulates Streptomyces metabolism at least through positive modulation of CCR.