Molecular Characterization of the cbh2 gene of Trichoderma viride

Total RNA was extracted, reverse transcribed, and the polymerase chain reaction performed to amplify the cDNA sequence of the Trichoderma viride cbh2 gene. A 1.5 kb amplified fragment bearing the coding sequence for the CBHII protein of T. viride and a 4.4 kb EcoRI fragment containing the cbh2 structural gene from a cloned, 14 kb San: fragment of genomic DNA were characterized. Structural analysis showed that the nucleotide sequences of Trichoderma cbh2 genes are highly conserved in evolution. Comparison of the regions upstream of the cellulase genes suggested that the difference in expression level of those genes may be attributed to the diversified regulatory sequences. The possible function of several determined unique sequences in the T. viride cbh2 flanking region is also discussed.