THE CLONING AND SEQUENCING OF A RIBOSOMAL L18 PROTEIN FROM AN EVOLUTIONARY DIVERGENT EUKARYOTE, TRYPANOSOMA-BRUCEI

Eukaryotic ribosomal proteins are highly conserved across widely diver gent species, suggesting that strong functional constraints prevent di vergence of important amino acid motifs. Using this as a basis, an evo lutionary approach could be used to identify putative functional motif s. We obtained the DNA sequence of the ribosomal protein L18 from the evolutionary divergent protozoan parasite, Trypanosoma brucei. Analysi s of this sequence showed that it had 46% and 43% identity with the hu man and yeast sequences, respectively, and 30% of amino acid residues were identical across all the species analysed. Using these data, amin o acids essential to the structure and function of ribosomal protein L 18 can be inferred and could provide valuable information for molecula r modelling and mutational studies.