Molecular cloning and expression of the novel fungal beta-glucosidase genes from Humicola grisea and Trichoderma reesei

J Biochem. 1999 Apr;125(4):728-36. doi: 10.1093/oxfordjournals.jbchem.a022343.

Abstract

A novel fungal beta-glucosidase gene (bgl4) and its homologue (bgl2) were cloned from the cellulolytic fungi Humicola grisea and Trichoderma reesei, respectively. The deduced amino acid sequences of H. grisea BGL4 and T. reesei BGL2 comprise 476 and 466 amino acids, respectively, and share 73.1% identity. These beta-glucosidases show significant homology to plant beta-glucosidases belonging to the beta-glucosidase A (BGA) family. Both genes were expressed in Aspergillus oryzae, and the recombinant beta-glucosidases were purified. Recombinant H. grisea BGL4 is a thermostable enzyme compared with recombinant T. reesei BGL2. In addition to beta-glucosidase activity, recombinant H. grisea BGL4 showed a significant level of beta-galactosidase activity, while recombinant T. reesei BGL2 showed weak beta-galactosidase activity. Cellulose saccharification by Trichoderma cellulases was improved by the addition of recombinant H. grisea BGL4.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Aspergillus oryzae / genetics
  • Base Sequence
  • Cellulase / metabolism
  • Cellulose / metabolism
  • Cloning, Molecular
  • DNA Primers / genetics
  • DNA, Fungal / genetics
  • Enzyme Stability
  • Gene Expression
  • Genes, Fungal*
  • Kinetics
  • Mitosporic Fungi / enzymology*
  • Mitosporic Fungi / genetics*
  • Molecular Sequence Data
  • Plants / enzymology
  • Plants / genetics
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Trichoderma / enzymology*
  • Trichoderma / genetics*
  • beta-Glucosidase / genetics*
  • beta-Glucosidase / metabolism

Substances

  • DNA Primers
  • DNA, Fungal
  • Recombinant Proteins
  • Cellulose
  • beta-Glucosidase
  • Cellulase

Associated data

  • GENBANK/AB003109
  • GENBANK/AB003110