Cloning, expression and partial characterization of a gene encoding the S15a ribosomal protein of Taenia solium

Ribosomes, ribosomal proteins (r-proteins), and messenger and transfer RNAs catalyze the synthesis of proteins in organisms. To understand and define the components involved in this event in Taenia solium, we isolated and characterized a T. solium cDNA encoding the basic ribosomal protein S15a (TsS15a). The TsS15a cDNA produces a protein with M-r (relative molecular mass) 14,988, which contains 22.3% of basic amino acids. Analysis comparing TsS15a protein with other S15a r-proteins indicates that this protein is highly conserved. A recombinant TsS15a protein with similar M-r was produced in bacteria. Antibodies against recombinant TsS15a react with a 15-kDa protein in extracts from all life stages of T. solium and from all helminths tested. Hybridization studies showed the presence of two genes encoding a mRNA of 0.5 kb. Moreover, the gene presents an intron of 30 bp. Our phylogenetic analysis using S15a r-proteins reproduced the topologies reported for 16/18S rRNA.