Isolation of a subtilisin-like serine protease gene (MyxSubtSP) from spores of Myxobolus cerebralis, the causative agent of whirling disease.

Proteases play important roles in parasite life cycles and host-parasite interactions. They are pathogenesis factors of many pathogenic organisms and are hence potential targets for chemotherapeutic treatment of disease. We identified a subtilisin-like serine protease gene, MyxSubtSP, expressed by Myxobolus cerebralis. After PCR with subtilisin-like serine protease primers, the gene was cloned, sequenced and aligned against the NCBI database. Its corresponding amino acid sequence included the putative conserved domains of Peptidase_S8, subtilase family and AprE, subtilisin-like serine proteases. Rapid amplification of 5' and 3' cDNA ends (RACE) was used to generate the full length (1385 bp) gene, with a 429 bp open reading frame. The gene encompasses coding regions for a catalytic triad formed by Asp-74, His-100 and Ser-110.