PEP-dependent, phosphoryl transfer-driven group translocators of the bacterial phosphoenolpyruvate:sugar phosphotransferase system (PTS) are the best characterized group translocators included in TC category 4. The product of the reaction, derived from extracellular sugar, is a cytoplasmic sugar-phosphate. Thus these systems are always uptake systems.  The enzymatic constituents, catalyzing sugar phosphorylation, are superimposed on the transport process in a tightly coupled process. The PTS is also involved in regulation and chemotaxis (Barabote & Saier et al., 2005;     Lengeler & Jahreis et al., 2009).  A compendium of articles about many different aspects of PTS function has appeared (J. Molec. Microbiol. Biotechnol., 25, #2-3, 2015; see Saier 2015 and Lengeler 2015 for overviews.  The PTS plays roles in the regulation of many bacterial physiological processes such as cyclic AMP synthesis, inducer exclusion, transcriptional regulation by several mechanisms, nitrogen metabolism, cytoplasmic K⁺ concentration, biofilm formation, and pathogenesis (Deutscher et al. 2014, Sutrina et al. 2015, Saier and Zhang 2015).