Abstract
Recent studies have revealed that the mechanisms of translation initiation in prokaryotes are diverse. To obtain some insight into the diversity of the nucleotide biases for translation initiation in prokaryotes, we conducted comparative analyses by using the genomes of 285 prokaryotes species. Previously we have invented a method to represent the statistical biases in nucleotide appearance at each position and evaluate the similarities of them. In this analysis, we applied this method to each species of 5' untranslated regions (5' UTRs). We then found that the Shine-Dalgarno (SD) sequence, a purine-rich region located upstream of the initiation codon existed among most of the species examined. The frequency patterns of the SD sequence vary depending on the taxonomy of species. However, the SD sequence did not appear among some species. The leaderless mRNA which has the initiation codon immediately at the 5' terminus was major among them. Additionally, some species show the mixed signals of them. These observations suggest that the diversity of the mechanisms of translation initiation in prokaryotes is related with sequence of the 3' end of 16S rRNA.