| Title |
Identification and Functional Analysis of a Gene Encoding β-Glucosidase from the Brown-Rot Basidiomycete Fomitopsis palustris |
| Author |
Hwang-Woo Ji and Chang-Jun Cha* |
| Address |
Microbial Biotechnology Lab, Department of Biotechnology (BK21-program), Chung-Ang University, Anseong 456-756, Republic of Korea |
| Bibliography |
Journal of Microbiology, 48(6),808-813, 2010,
|
| DOI |
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| Key Words |
β-glucosidase, F. palustris, brown-rot fungus, glycosyl hydrolase, P. pastoris |
| Abstract |
The brown-rot basidiomycete Fomitopsis palustris is known to degrade crystalline cellulose (Avicel) and produce three major cellulases, exoglucanases, endoglucanases, and β-glucosidases. A novel β-glucosidase designated as Cel3A was identified from F. palustris grown at the expense of Avicel. The deduced amino acid sequence of Cel3A showed high homology with those of other fungal β-glucosidases that belong to glycosyl hydrolase (GH) family 3. The sequence analysis also indicated that Cel3A contains the N- and C-terminal domains of GH family 3 and Asp-209 was conserved as a catalytic nucleophile. The cloned gene was successfully expressed in the yeast Pichia pastoris and the recombinant protein exhibited β-glucosidase activity with cellobiose and some degree of thermostability. Considering the size and sequence of the protein, the β-glucosidase identified in this study is different from the protein purified directly from F. palustris in the previous study. Our results suggest that the fungus possesses at least two β-glucosidase genes. |
