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 (PubMed:3129430, PubMed:10562420). Also functions as a chemoreceptor monitoring the environment for changes in sugar concentration and an effector modulating the activity of the transcriptional repressor Mlc (PubMed:18319344). (Microbial infection) Probably transports the toxic C-terminal region of CdiA from E.coli strains NC101 and 3006 across the inner membrane to the cytoplasm, where CdiA degrades specific tRNAs. Toxin transport is strain-specific, mutations in this gene do not confer resistance to several other tested CdiA toxins (PubMed:26305955). Probably also serves as the inner membrane receptor for CdiA-STECO31 from E.coli strain STEC_O31 (Probable). D-glucose(out) + N(pros)-phospho-L-histidyl-[protein] = D-glucose 6-phosphate(in) + L-histidyl-[protein] Transporter activity may be inhibited by SgrT. Homodimer. The ptsG transcript is degraded under conditions of glucose-phosphate stress (due to intracellular accumulation of glucose-6-phosphate caused by disruption of glycolytic flux), or in the presence of (toxic) non-metabolizable glucose phosphate analogs due to hybridization with the small RNA sgrS (originally known as ryaA). This hybridization is sufficient to repress mRNA translation (PubMed:16549791). The hybrid is subsequently degraded by RNase E. This reduces the quantity of transporter and relieves glucose phosphate stress. The EIIB domain is phosphorylated by phospho-EIIA on a cysteinyl or histidyl residue, depending on the transported sugar. Then, it transfers the phosphoryl group to the sugar substrate concomitantly with the sugar uptake processed by the EIIC domain. The EIIC domain forms the PTS system translocation channel and contains the specific substrate-binding site. Disruption confers resistance to cellular contact-dependent growth inhibition (CDI) CdiA of E.coli strains NC101 and 3006, but not to several other tested CdiA toxins (PubMed:26305955). Disruption confers resistance to cellular contact-dependent growth inhibition (CDI) CdiA-STECO31 of E.coli strain STEC_O31 (PubMed:28351921).