Transcriptional regulation of the bgl operon of Escherichia coli involves phosphotransferase system‐mediated phosphorylation of a transcriptional antiterminator

The bgl operon of Escherichia coli is regulated by a novel two-component regulatory system which consists of a sensory protein, BglF, present in the cytoplasmic membrane and a regulatory protein, BglG, present in the cytoplasm. The sensor is a phosphotransferase system (PTS) transport protein which controls the activity of the regulatory protein according to substrate availability. The regulator is an RNA binding protein which controls operon expression by transcriptional antitermination. In the absence of substrate, BglF phosphorylates BglG thus inactivating it. In the presence of substrate, BglF removes the phosphate from BglG thus allowing it to function as an antiterminator. In this review we focus on the interactions between the sensor and regulator of the bgl system and discuss other systems that are regulated in a similar way.