Abstract: CyP protein family plays an important role in the process of protein folding. In this study, a novel silkworm gene BmCyPA was cloned, which comprises 2 exons and 1 intron. The deduced BmCyPA protein contains 165 amino acids, its molecular mass is 19.4 kD and pI is 8.79. Sequences analysis showed that BmCyPA is highly conserved among different species. The BmCyPA protein has peptidylprolyl cis-trans-isomerase active sites and contains specific amino acids which can bind to the side chain of CsA, which indicated that BmCyPA has potential cis-trans-isomerase activtity and can combine with CsA. RT-PCR of tissue expression pattern and EST analysis revealed that BmCyPA is specifically and highly expressed in silk gland. The potential function of BmCyPA gene was further analyzed by phylogenetic analysis of CyPA genes from different species. The results suggest that BmCyP may be involved in the process of fibroin folding.

Key words: Bombyx mori, CyP gene, silk gland, gene cloning, phylogeny, expression pattern