A CHITINASE ENCODING GENE (CHIT1 GENE) FROM THE ENTOMOPATHOGEN METARHIZIUM-ANISOPLIAE - ISOLATION AND CHARACTERIZATION OF GENOMIC AND FULL-LENGTH CDNA

There are no reports to date of entire gene sequences coding for chiti nolytic enzymes from entomopathogenic fungi, even though these enzymes act synergistically with proteolytic enzymes to solubilize insect cut icle during the key step of host penetration, having considerable impo rtance in the biological control of some insect pests. This paper repo rts the complete nucleotide sequence and analysis of the chromosomal a nd full-length cDNA copies of the regulated gene (chit1) coding one of the chitinases produced by the biocontrol agent Metarhizium anisoplia e. Degenerated primers, encompassing conserved regions of other fungal chitinases, were used to amplify a 650-bp DNA fragment, which was use d to isolate genomic and cDNA clones from M. anisopliae. Albeit at lea st two different chitinases are characterized in this fungus, only one chit gene was isolated. The chit1 gene is interrupted by three short typical fungal introns and has a 1,521-bp ORE which encodes a protein of 423 amino acids with a stretch of 35 amino acid residues displaying characteristics of signal peptide. The deduced sequence of the mature protein predicts a 42-kDa protein with pi of 5.8. Southern analysis o f genomic DNA indicates a single copy of chit1 in the M. anisopliae ge nome.