Description | The phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS) [ , ] is a major carbohydrate transport system in bacteria. The PTS catalyses the phosphorylation of incoming sugar substrates and coupled with translocation across the cell membrane, makes the PTS a link between the uptake and metabolism of sugars.The general mechanism of the PTS is the following: a phosphoryl group from phosphoenolpyruvate (PEP) is transferred via a signal transduction pathway, to enzyme I (EI) which in turn transfers it to a phosphoryl carrier, the histidine protein (HPr). Phospho-HPr then transfers the phosphoryl group to a sugar-specific permease, a membrane-bound complex known as enzyme 2 (EII), which transports the sugar to the cell. EII consists of at least three structurally distinct domains IIA, IIB and IIC [ ]. These can either be fused together in a single polypeptide chain or exist as two or three interactive chains, formerly called enzymes II (EII) and III (EIII).The Man family is unique in several respects among PTS permease families:It is the only PTS family in which members possess a IID protein.It is the only PTS family in which the IIB constituent is phosphorylated on a histidyl rather than a cysteyl residue.Its permease members exhibit broad specificity for a range of sugars, rather than being specific for just one or a few sugars.This family consists only of glucitol-specific transporters, and occur both in Gram-negative and Gram-positive bacteria. The system in Escherichia coli consists of a IIA protein, and a IIBC protein. This family is specific for the IIA component. | Name | Phosphotransferase system, glucitol/sorbitol-specific IIA component, subgroup |
Short Name | PTS_IIA_glucitol/sorbitol_sub | Type | Family |