CLONING AND EXPRESSION OF THE GENE ENCODING THERMOANAEROBACTER ETHANOLICUS 39E SECONDARY-ALCOHOL DEHYDROGENASE AND ENZYME BIOCHEMICAL CHARACTERIZATION

摘要

The adhB gene encoding Thermoanaerobacter ethanolicus 39E secondary-alcohol dehydrogenase (2-Adh) was cloned, sequenced, and expressed in Escherichia coli. Both the nucleic acid sequence coding for the enzyme and the amino acid sequence are reported. The purified recombinant enzyme is homotetrameric consisting of 37.7 kDa subunits and optimally active above 90 °C with a half-life of approximately of 1.7 h at 90 °C. The enzyme has a substantial preference in the oxidation of secondary alcohols over primary alcohols.