MOLECULAR CHARACTERIZATION AND HETEROLOGOUS EXPRESSION OF AN ENDO-BETA-1,6-GLUCANASE GENE FROM THE MYCOPARASITIC FUNGUS TRICHODERMA-HARZIANUM

Hydrolytic enzymes from the filamentous fungus Trichoderma harzianum h ave been described as critical elements of the mycoparasitic action of Trichoderma against fungal plant pathogens. In this report we describ e the first genomic and cDNA clones encoding a beta-1,6-endoglucanase gene. The deduced protein sequence has limited homology with other bet a-glucanases. Northern experiments show a marked repression of mRNA ac cumulation by glucose. The protein has been successfully produced in S accharomyces cerevisiae upon construction of a transcriptional fusion of the cDNA with a yeast promoter. This S. cerevisiae recombinant stra in shows a strong lytic action on agar plates containing beta-1,6-gluc an.