[Cloning and expression in yeasts of the class V chitinase cDNA gene from Trichoderma harzianum]

To explore the integrated bio-control mechanism of Trichoderma harzianum and acquire some bio-control associated novel genes, a Trichoderma harzianum mycelium cDNA library has been constructed and thereby randomly selected clones were sequenced and analyzed by bioinformatics analysis. Full-length cDNA, encoding class v chitinase (ChiV), successfully cloned. The results indicated that the ORF of ChiV was 1194 bp, encoding 397 aa, deduced molecular weight 44 kD. The gene was ligated to the vector of pYES2 and thereby transformed to the yeast of H158 species. The enzyme activity reached the peak expression after cultured for 60 h induced by beta-galactose. The optimal temperature of ChiV is 37 degrees C and the optimal pH is 6 and 8.