title: Improvement of cellulose-degrading ability of a yeast strain displaying Trichoderma reesei endoglucanase II by recombination of cellulose-binding domains.
abstract: To improve the cellulolytic activity of a yeast strain displaying endoglucanase II (EGII) from the filamentous fungus Trichoderma reesei QM9414, the genes encoding the cellulose-binding domain (CBD) of EGII, cellobiohydrolase I (CBHI) and cellobiohydrolase II (CBHII) from T. reesei QM9414, were fused with the catalytic domain of EGII and expressed in Saccharomyces cerevisiae. Display of each of the recombinant EGIIs was confirmed using immunofluorescence microscopy. In the case of EGII-displaying yeast strains in which the CBD of EGII was replaced with the CBD of CBHI or CBHII, the binding affinity to Avicel and hydrolytic activity toward phosphoric acid swollen Avicel were similar to that of a yeast strain displaying wild-type EGII. On the other hand, the three yeast strains displaying EGII with two or three tandemly aligned CBDs showed binding affinity and hydrolytic activity higher than that of the yeast strain displaying wild-type EGII. This result indicates that the hydrolytic activity of yeast strains displaying recombinant EGII increases with increased binding ability to cellulose.
authors.affiliation: Department of Chemical Science and Engineering, Faculty of Engineering, and Division of Molecular Science, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Ito
authors.forename: Yasuya
authors.initials: Y
authors.lastname: Fujita
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ueda
authors.forename: Hideki
authors.initials: H
authors.lastname: Fukuda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D001673:Biodegradation, Environmental; D002384:Catalysis; D020134:Catalytic Domain; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D004789:Enzyme Activation; D000431:Ethanol / Q000378:metabolism; D024861:Genetic Enhancement / Q000379:methods; D011485:Protein Binding; D015202:Protein Engineering / Q000379:methods; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D014170:Transformation, Genetic; D014242:Trichoderma / Q000201:enzymology* / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D000431:Ethanol; D002482:Cellulose; C056373:endoglucanase 2; D002480:Cellulase