Cloning and characterization of a chitinase (CHIT42) cDNA from the mycoparasitic fungus Trichoderma harzianum

• Published in: Current genetics Vol. 27; no. 1; p. 83
• Main Authors: Garcia, I, Lora, J.M, Cruz, J. de la, Benitez, T, Llobell, A, Pintor-Toro, J.A. (Consejo Superior de Investigaciones Cientificas, Sevilla (Spain). Inst. de Recursos Naturales y Agrobiologia)
• Format: Journal Article
• Language: English
• Published: United States 01.12.1994
• Subjects: ADN; Amino Acid Sequence; Base Sequence; CHITINASE; Chitinases - biosynthesis; Chitinases - genetics; CHITINE; CLONACION MOLECULAR; CLONAGE MOLECULAIRE; Cloning, Molecular; CONTROL BIOLOGICO; DNA, Complementary - genetics; DNA, Fungal - genetics; Enzyme Induction; Fungal Proteins - biosynthesis; Fungal Proteins - genetics; GENE; Gene Expression Regulation, Fungal; GENES; Genes, Fungal; Isoenzymes - biosynthesis; Isoenzymes - genetics; LUTTE BIOLOGIQUE; Molecular Sequence Data; PARASITISME; PARASITISMO; Protein Conformation; QUITINA; QUITINASA; SECUENCIA NUCLEOTIDICA; Sequence Alignment; Sequence Homology, Amino Acid; SEQUENCE NUCLEOTIDIQUE; Species Specificity; Trichoderma - enzymology; Trichoderma - genetics; TRICHODERMA HARZIANUM
• ISSN: 0172-8083; 1432-0983
• DOI: 10.1007/bf00326583

A cDNA of Trichoderma harzianum-(chit42), coding for an endochitinase of 42 kDa, has been cloned using synthetic oligonucleotides corresponding to aminoacid sequences of the purified chitinase. The cDNA codes for a protein of 423 amino acids. Analysis of the N-terminal amino-acid sequence of the chitinase, and comparison with that deduced from the nucleotide sequence, revealed post-translational processing of a putative signal peptide of 22 amino acids and a second peptide of 12 amino acids. The chit42 sequence presents overall similarities with filamentous fungal and bacterial chitinases and to a lesser extent with yeast and plant chitinases. The deduced aminoacid sequence has putative catalytic, phosphorylation and glycosylation domains. Expression of chit42 mRNA is strongly induced by chitin and chitin-containing cell walls and is subjected to catabolite repression. Southern analysis shows that it is present as a single-copy gene in T. harzianum. chit42 is also detected in several tested mycoparasitic and non-mycoparasitic fungal strains.