IUBMB Enzyme Nomenclature


Accepted name: protein-Nπ-phosphohistidine—trehalose phosphotransferase

Reaction: [protein]-Nπ-phospho-L-histidine + α,α-trehalose[side 1] = [protein]-L-histidine + α,α-trehalose 6-phosphate[side 2]

Other name(s): treB (gene name); trehalose PTS permease; EIITre; Enzyme IITre

Systematic name: protein-Nπ-phospho-L-histidine:α,α-trehalose Nπ-phosphotransferase

Comments: This enzyme is a component (known as enzyme II) of a phosphoenolpyruvate (PEP)-dependent, sugar transporting phosphotransferase system (PTS). The system, which is found only in prokaryotes, simultaneously transports its substrate from the periplasm or extracellular space into the cytoplasm and phosphorylates it. The phosphate donor, which is shared among the different systems, is a phospho-carrier protein of low molecular mass that has been phosphorylated by EC (phosphoenolpyruvate—protein phosphotransferase). Enzyme II, on the other hand, is specific for a particular substrate, although in some cases alternative substrates can be transported with lower efficiency. The reaction involves a successive transfer of the phosphate group to several amino acids within the enzyme before the final transfer to the substrate.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Boos, W., Ehmann, U., Forkl, H., Klein, W., Rimmele, M. and Postma, P. Trehalose transport and metabolism in Escherichia coli, J. Bacteriol. 172 (1990) 3450-3461. [PMID: 2160944]

2. Klein, W., Horlacher, R. and Boos, W. Molecular analysis of treB encoding the Escherichia coli enzyme II specific for trehalose. J. Bacteriol. 177 (1995) 4043-4052. [PMID: 7608078]

[EC created 1972 as EC, part transferred 2016 to EC]

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