Phosphotransferase system, fructose-specific IIB subunit (IPR003353)

Short name: PTS_IIB_fruc

Overlapping homologous superfamilies

Domain relationships


The bacterial phosphoenolpyruvate: sugar phosphotransferase system (PTS) is a multi-protein system involved in the regulation of a variety of metabolic and transcriptional processes. The PTS catalyzes the phosphorylation of incoming sugar substrates concomitant with their translocation across the cell membrane. The general mechanism of the PTS is the following: a phosphoryl group from phosphoenolpyruvate (PEP) is transferred to enzyme-I (EI) of PTS which in turn transfers it to a phosphoryl carrier protein (HPr). Phospho-HPr then transfers the phosphoryl group to a sugar-specific permease which consists of at least three structurally distinct domains (IIA, IIB, and IIC) [PMID: 1537788] which 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). IIB (EC: is is phosphorylated by phospho-IIA, before the phosphoryl group is transferred to the sugar substrate.

Several PTS permease families are currently recognised, namely, the (i) glucose (including glucoside), (ii) fructose (including mannitol), (iii) lactose (including N,N-diacetylchitobiose), (iv) galactitol, (v) glucitol, (vi) mannose, and (vii) l-ascorbate families [PMID: 16339738].

This entry represents the component EIIB of fructose-specific PTS systems.

GO terms

Biological Process

GO:0009401 phosphoenolpyruvate-dependent sugar phosphotransferase system

Molecular Function

GO:0022877 protein-N(PI)-phosphohistidine-fructose phosphotransferase system transporter activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.