Ribosomal RNA genes from Prevotella bryantii: organization and heterogeneity

Five P. bryantii B(1)4 16S rRNA gene copies and their flanking regions were cloned and analyzed. A genomic library was constructed and screened with oligonucleotide DNA probe specific for 16S rRNA gene of P. bryantii. Five out of six different copies of 16S RNA gene were recovered and sequenced. Only minor differences (0.3-1.2%) between copies were detected within the 1541 bp long sequence. The impact of the sequence variability of 16S rRNA gene copies on phylogenetic positioning of P. bryantii was determined. All five sequences from cloned P. bryantii B(1)4 16S rRNA genes were placed in the same operational taxonomy unit. Control regions of all five analyzed rRNA operons were almost identical and three candidate for promoter sequences were identified by Neutral Network Promoter Prediction. Spacer regions between 16S rRNA and 23S rRNA genes in all five cloned copies were 543 bp long and genes for tRNA(Ile) and tRNA(Ala) were identified inside this regions.