Figure 1From: Unraveling the evolutionary history of the phosphoryl-transfer chain of the phosphoenolpyruvate:phosphotransferase system through phylogenetic analyses and genome contextSchematic representation of the PTS phosphoryl transfer chain. As examples, mannose-class and lactose-class PTS transporters are depicted. Phosphoryl groups are sequentially transferred from PEP to EI, HPr, and subsequently to the transporter subunits IIA. The phosphoryl group is finally transferred from the IIB domain to the incoming sugar. Phosphorylation of HPr by HPrK at Ser(46) is also indicated.Back to article page