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. 1996 Feb 5;250(2):197-206. doi: 10.1007/BF02174179.


The Klebsiella pneumoniae genes scrA and scrB are indispensable for sucrose (Scr) utilisation. Gene scrA codes for an Enzyme IIScr (IIScr) transport protein of the phosphoenolpyruvate-dependent carbohydrate: phosphotransferase system (PTS), while scrB encodes a sucrose 6-phosphate specific invertase. A 3.7 kbscr AB DNA fragment has been cloned from K. pneumoniae and expressed in Escherichia coli. Its nucleotide sequence was determined and the coding regions for scrA (1371 bp) and scrB (1401 bp) were identified by genetic complementation, enzyme activity test and radiolabelling of the gene products. In addition, the nucleotide sequence of the scrB gene from conjugative plasmid pUR400 isolated from Salmonella typhimurium was also determined and errors in the previously published sequence of the scrA gene of pUR400 were corrected. Extensive similarity was found between the sequences of ScrA and other Enzymes II, as well as between the two invertases and other sucrose hydrolysing enzymes. Based on the analysis of seven IIScr proteins, a hypothetical model of the secondary structure of IIScr is proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites / genetics
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA-Directed RNA Polymerases / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / genetics
  • Gene Expression / genetics
  • Genes, Bacterial
  • Glycoside Hydrolases / chemistry
  • Glycoside Hydrolases / genetics*
  • Glycoside Hydrolases / metabolism
  • Klebsiella pneumoniae / enzymology
  • Klebsiella pneumoniae / genetics*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Molecular Sequence Data
  • Phosphoenolpyruvate Sugar Phosphotransferase System / chemistry
  • Phosphoenolpyruvate Sugar Phosphotransferase System / genetics*
  • Phosphoenolpyruvate Sugar Phosphotransferase System / metabolism
  • Plasmids
  • Promoter Regions, Genetic / genetics
  • Protein Structure, Secondary
  • Ribosomes / metabolism
  • Salmonella typhimurium / genetics
  • Sequence Analysis
  • Sequence Homology, Nucleic Acid
  • Sucrose / metabolism
  • Viral Proteins
  • beta-Fructofuranosidase


  • Membrane Proteins
  • Viral Proteins
  • Sucrose
  • Phosphoenolpyruvate Sugar Phosphotransferase System
  • phosphoenolpyruvate-sucrose phosphotransferase
  • bacteriophage T7 RNA polymerase
  • DNA-Directed RNA Polymerases
  • Glycoside Hydrolases
  • beta-Fructofuranosidase

Associated data

  • GENBANK/L06761
  • GENBANK/M22711
  • GENBANK/M33761
  • GENBANK/M76768
  • GENBANK/X57401
  • GENBANK/X67750
  • GENBANK/X69800