The Prokaryote-specific Phosphotransferase System PTS

The PTS catalyzes group translocation, the coupling of sugar transport to sugar phosphorylation. Phosphoenolpyruvate is the initial phosphoryl donor. It phosphorylates Enzyme L and then the phos-phoryl group is sequentially passed to HPr, Enzyme DA, Enzyme IIB, and finally to an incoming sugar 

Strain differences within a single species show surprising differences in PTS content. For example, various strains of Strep, pyogenes may have or lack a dihydroxyacetone (DHA)-PTS, while various strains of Strep, agalactiae differ with respect to the presence or absence of an extra lactose (Lac) permease. Finally, Strep, pneumoniae strains differ with respect to the presence of a fructose (Fru) system and whether or not IIA Fru is fused to a BglG-like transcriptional regulator (Barabote and Saier 2005). 

Further studies revealed that, over evolutionary time, fusion and spUcing of PTS proteins to give proteins of varying sizes and domain compositions have occurred frequently. Moreover, 

2 Lactose PTS group translocator 1 Lact. gasseri Francl et al. 2012 

---