Analysis of RNA Editing in Conserved Sequence Blocks of the Trypanosomatid RPS12 Gene

The RPS12 gene in the mitochondrial genome encodes an important protein from the small ribosomal subunit. The transcript of this gene can undergo RNA editing in a number of organisms, for instance it is edited actively in all tripanosomatida. In this study, a comparison between the sequences of edited mRNA and tertiary structures of the proteins when mRNA were translated from some of the members of Tripanosomatidae family showed that tertiary structures of the RPS12 gene remained unchanged in all species while only two short conserved regions were found in the primary structure of the gene. Using computer modeling it was demonstrated that these regions encode amino acids that are turned in the decoding center of the ribosome. The nature of editing patterns demonstrates that evolutionary conservation of these regions is independent of the editing process; moreover, an evolutionary tendency to reduction of editing process in a number of sites was seen within the conserved sites of the RPS12 gene.