Characterization of a novel metagenome-derived 6-phospho-β-glucosidase from black liquor sediment.

ABSTRACT: The enzyme 6-phospho-β-glucosidase is an important member of the glycoside hydrolase family 1 (GH1). However, its catalytic mechanisms, especially the key residues determining substrate specificity and affinity, are poorly understood. A metagenome-derived gene sequence, encoding a novel 6-phospho-β-glucosidase designated Pbgl25-217, was isolated and characterized. The optimal conditions for enzymatic activity were 37°C and pH 7; Ca(2+), Mg(2+), and Mn(2+) stabilized the activity of Pbgl25-217, whereas Ni(2+), Fe(2+), Zn(2+), Cu(2+), and Fe(3+) inhibited its activity. The Km and Vmax of Pbgl25-217 were 4.8 mM and 1,987.0 U mg(-1), respectively. Seven conserved residues were recognized by multiple alignments and were tested by site-directed mutagenesis for their functions in substrate recogn

SUBMITTER: Yang C 

PROVIDER: S-EPMC3623223 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature