Cloning and characterization of a chitinase (chit42) cDNA from the mycoparasitic fungus Trichoderma harzianum.
A cDNA of Trichoderma harzianum (chit42), coding for an endochitinase of 42 kDa, has been cloned using synthetic oligonucleotides corresponding to amino-acid 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 amino-acid 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.
García
I
I
Instituto de Recursos Naturales y Agrobiología, Sevilla, Spain.
Lora
J M
JM
de la Cruz
J
J
Benítez
T
T
Llobell
A
A
Pintor-Toro
J A
JA
D000595:Amino Acid Sequence; D001483:Base Sequence; D002688:Chitinases / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics*; D004790:Enzyme Induction; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014242:Trichoderma / Q000201:enzymology / Q000235:genetics*
D018076:DNA, Complementary; D004271:DNA, Fungal; D005656:Fungal Proteins; D007527:Isoenzymes; D002688:Chitinases