Abstract: Isaria cicadae is one of the most common species of entomopathogenic fungi, and has been used as biocontrol agents against pests. In order to obtain a complete cDNA of sublitisin-like protease from I. cicadae, a pair of primers was designed using MegAign of DNAStar analysis software according to the high conserved nucleotide sequences in GenBank, and RT-PCR, 3'/5'-RACE PCR were used. The whole sequence of cloned cDNA was 2 031 bp, and the results showed that it had 170 bp and 262 bp on the 5'-terminal and 3'-terminal respectively, encompassed an open reading frame (ORF) with 1 599 bp encoding 532 amino acid (aa) residues, including 18-aa signal peptide, 133-aa propeptide. Alignments with the deduced amino acid of proteins in the species of Isaria farinose, Beauveria bassiana, Cordyceps militaris and Trichoderma harzianum showed a homology of 88%, 88%, 89% and 71%, respectively. The sublitisin-like protease of I. cicadae was located in the vacuoles of cells associated with the secretory pathway, with 5 cycteines and 4 putative N-glycosylation sites. The secondary structure of the protein was mainly the α-helix and randon coil.

Key words: Entomogenous fungi, Isaria cicadae, sublitisin-like protease gene, cloning