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 complex composed of PtsG and Crr is involved in glucose transport. Binds 1 zinc ion per glycerol kinase EIIA-Glc dimer. The zinc ion is important for dimerization. Heterodimer with glycerol kinase (glpk). The EIIA domain is phosphorylated by phospho-HPr on a histidyl residue. Then, it transfers the phosphoryl group to the EIIB domain.