Cloning and characterization of cbhII gene from Trichoderma parceramosum and its expression in Pichia pastoris

Abstract

The genomic and cDNA clones encoding cellobiohydrolase II (CBHII) have been isolated and sequenced from a native Iranian isolate of Trichoderma parceramosum, a high cellulolytic enzymes producer isolate. This represents the first report of cbhII gene from this organism. Comparison of genomic and cDNA sequences indicates this gene contains three short introns and also an open reading frame coding for a protein of 470 amino acids. The deduced amino acid sequence includes a putative signal peptide, cellulose binding<br />domain, linker region, and catalytic domain. Homology between this sequence and other reported Trichoderma<br />CBHII proteins and also structural prediction of this enzyme are discussed. The coding sequence of cbhII gene was cloned in pPIC9 expression vector and expressed in Pichia pastoris GS115. The expression was confirmed by Northern dot blot, RT-PCR and enzyme activity staining.