Xylose (glucose) isomerase gene from the thermophile Clostridium thermohydrosulfuricum; cloning, sequencing, and expression in Escherichia coli

Agric Biol Chem. 1991 Jan;55(1):221-7.


The xylose isomerase gene from the thermophile Clostridium thermohydrosulfuricum has been cloned, using a fragment of the Bacillus subtilis gene as a probe. The complete nucleotide sequence of the gene was analyzed. C. thermohydrosulfuricum is the most thermophilic organism from which a xylose isomerase gene has been cloned and characterized. Comparison with amino acid sequences from other xylose isomerases showed that amino acids involved in substrate binding and isomerization are well conserved. Purification of the enzyme produced in E. coli was done by heating a cell-free extract at 85 degrees C for 10 min, giving a 20-fold purified enzyme. The native enzyme is a homomeric tetramer with a molecular weight of 200,000.

MeSH terms

  • Aldose-Ketose Isomerases*
  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Carbohydrate Epimerases / biosynthesis
  • Carbohydrate Epimerases / genetics*
  • Cloning, Molecular
  • Clostridium / enzymology
  • Clostridium / genetics*
  • Escherichia coli / genetics*
  • Gene Expression
  • Molecular Sequence Data
  • Molecular Structure
  • Plasmids / genetics
  • Protein Engineering
  • Recombinant Proteins / biosynthesis
  • Sequence Homology, Nucleic Acid


  • Recombinant Proteins
  • Carbohydrate Epimerases
  • Aldose-Ketose Isomerases
  • xylose isomerase