IUBMB Enzyme Nomenclature


Accepted name: protein-Nπ-phosphohistidine—sucrose phosphotransferase

Reaction: [protein]-Nπ-phospho-L-histidine + sucrose[side 1] = [protein]-L-histidine + sucrose 6G-phosphate[side 2]

Other name(s): scrAB (gene names); sucrose PTS permease; EIIScr; Enzyme IIScr

Systematic name: protein-Nπ-phospho-L-histidine:sucrose 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. St Martin, E.J. and Wittenberger, C.L. Characterization of a phosphoenolpyruvate-dependent sucrose phosphotransferase system in Streptococcus mutans. Infect. Immun. 24 (1979) 865-868. [PMID: 468378]

2. Lunsford, R.D. and Macrina, F.L. Molecular cloning and characterization of scrB, the structural gene for the Streptococcus mutans phosphoenolpyruvate-dependent sucrose phosphotransferase system sucrose-6-phosphate hydrolase. J. Bacteriol. 166 (1986) 426-434. [PMID: 3009399]

3. Fouet, A., Arnaud, M., Klier, A. and Rapoport, G. Bacillus subtilis sucrose-specific enzyme II of the phosphotransferase system: expression in Escherichia coli and homology to enzymes II from enteric bacteria. Proc. Natl. Acad. Sci. USA 84 (1987) 8773-8777. [PMID: 3122206]

4. Sato, Y., Poy, F., Jacobson, G.R. and Kuramitsu, H.K. Characterization and sequence analysis of the scrA gene encoding enzyme IIScr of the Streptococcus mutans phosphoenolpyruvate-dependent sucrose phosphotransferase system. J. Bacteriol. 171 (1989) 263-271. [PMID: 2536656]

5. Titgemeyer, F., Jahreis, K., Ebner, R. and Lengeler, J.W. Molecular analysis of the scrA and scrB genes from Klebsiella pneumoniae and plasmid pUR400, which encode the sucrose transport protein Enzyme II Scr of the phosphotransferase system and a sucrose-6-phosphate invertase. Mol. Gen. Genet. 250 (1996) 197-206. [PMID: 8628219]

6. Jiang, L., Cai, J., Wang, J., Liang, S., Xu, Z. and Yang, S.T. Phosphoenolpyruvate-dependent phosphorylation of sucrose by Clostridium tyrobutyricum ZJU 8235: evidence for the phosphotransferase transport system. Bioresour. Technol. 101 (2010) 304-309. [PMID: 19726178]

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

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