The phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS), a major carbohydrate active transport system, catalyzes the phosphorylation of incoming sugar substrates concomitant with their translocation across the cell membrane. The enzyme II SorABFM PTS system is involved in L-sorbose transport. By L-sorbose. The EIIC type-4 domain forms the PTS system translocation channel and contains the specific substrate-binding site.