Abstract:A clone from Clonorchis sinensis full-length cDNA plasmid library was recognized as a putative small multidrug/metabolites efflux protein-like gene,and the structural and functional characteristics of the putative protein were analyzed by on-line bioinformatics tools provided by NCBI(http://www.ncbi.nlm.nih.gov/,ExPaSy(http://www.ncbi.nlm.nih.gov/),and CBS Prediction Servers(http://www.cbs.dtu.dk/services/) and Vector NTI suite 8.0 software package,and its application was predicted on the basis of the bioinformatics.It was found that gene contained a complete cds encoding 189 amino acids containing 5 transmembrane regions with the N terminus inside of the cytoplasm membrane and C terminus outside.It belong to the subfamily of MFS-1 of the Major Facility Superfamily with the property of small multidrug/metabolites efflux protein,which was characterized by 4 or 5 transmembrane regions.Comparing with the homologue of Schistosoma japonicum(with identity of 67% and similarity of 80%),each of four of five transmembrane regions contains one or two conserved basic amino acid residue arginine or histidine and there are several phosphorylation sites and linear T cell and B cell epitopes mainly located in the outside of membrane.These suggest the protein maybe locate in the membrane of tegument of C.sinensis and is involved in the pump-out of anionic drugs or deleterious metabolites,and is a potential candidate of vaccine and immunodiagnosis for clonorchiasis.