The phosphoenolpyruvate-dependent sugar phosphotransferase system (sugar PTS), a major carbohydrate active transport system, catalyzes the phosphorylation of incoming sugar substrates concomitantly with their translocation across the cell membrane. The enzyme II FruAB PTS system is involved in fructose transport. Part of the fruBKA (fru) operon, which is induced in the presence of fructose via the FruR (Cra) regulatory protein (PubMed:33476373). Transcription is repressed by FruR in the absence of fructose (PubMed:33649152). CRP activates expression of the fru operon in the absence of glucose (PubMed:33649152). The two regulators can work independently to control the expression of the operon depending on carbon source availability (PubMed:33649152). The PTS EIIA type-2 domain is phosphorylated by phospho-HPr on a histidyl residue. Then, it transfers the phosphoryl group to the PTS EIIB type-2 domain. In contrast to classical PTS systems, the fructose-specific PTS has no requirement for HPr; FruB combines a IIA domain with a HPr domain. Does not affect growth on glucose. Mutant shows a slight growth retardation on fructose.