Molecular Cloning and Characterization of an Enzyme Hydrolyzing p-Nitrophenyl α-D-Glucoside from Bacillus stearothermophilus SA0301
<I>Bacillus stearothermophilus</I> SA0301 produces an extracellular oligo-1,6-glucosidase (bsO16G) that also hydrolyzes <I>p</I>-nitrophenyl α-<small>D</small>-glucoside (Tonozuka <I>et al.</I>, <I>J. Appl. Glycosci.</I>, <B>45</B>, 397–400 (1998)). We cloned a gene for an enzyme hydrolyzing <I>p</I>-nitrophenyl α-<small>D</small>-glucoside, which was different from the one mentioned above, from <I>B. stearothermophilus</I> SA0301. The <I>k</I><SUB>0</SUB>⁄<I>K</I><SUB>m</SUB> values of bsO16G for isomaltotriose and isomaltose were 13.2 and 1.39 s<SUP>−1</SUP>·m<small>M</small><SUP>−1</SUP> respectively, while the newly cloned enzyme did not hydrolyze isomaltotriose, and the <I>k</I><SUB>0</SUB>⁄<I>K</I><SUB>m</SUB> value for isomaltose was 0.81 s<SUP>−1</SUP>·m<small>M</small><SUP>−1</SUP>. The primary structure of the cloned enzyme more closely resembled those of trehalose-6-phosphate hydrolases than those of oligo-1,6-glucosidases, and the cloned enzyme hydrolyzed trehalose 6-phosphate. An open reading frame encoding a protein homologous to the trehalose-specific IIBC component of the phopshotransferase system was also found upstream of the gene for this enzyme.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(2), 495-499, 2006-02-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry