This project comprises the investigation of reversible protein ADP-ribosylation and its impact on bacterial metabolism, using the genetic model of Streptomyces coelicolor A3(2), an industrially important bacterium from the genus Streptomyces, which produces over two-thirds of all clinically useful antibiotics of natural origin. Bacteria, and Streptomyces in particular are known to utilize protein ADP-ribosylation to control a variety of important pathways (such as morphological differentiation and antibiotic production), but the proteins involved in this regulation are mostly unknown (transferases and hydrolases). The goal of this project is the identification and characterization of the enzymes controlling reversible protein ADP-ribosylation, as well as the pathways and protein targets for their regulation in Streptomyces.