Molecular cloning and sequence analysis of the endochitinase from Chaetomium cupreum

Endochitinase gene fragment of Chaetomium cupreum (designated Chi46) obtained by construction of C. cupreum mycelium cDNA library. Its full-length cDNA was cloned by PCR. The results showed that the open reading frame of Chi46 was 1350bp and encoded a putative protein of 449 amino acids residues with s molecular mass of 46kDa. Bioinformatics analysis revealed that protein sequence of Chi46 containing a 22-residue secretion signal sequence and had a high degree of similarity with C. globosum chitinase. The domain search program at the NCBI and Pfam server showed that Chi46 protein had the glycosyl-hydrolase-18 conserved domain. Additionally, the deduced amino acid sequence had the same catalytic domain and substrate binding site with ech42 of Trichoderma harzianum.