Presence of tRNAala-tRNAile genes in the 16S-23S rDNA spacer sequence and two rrn operons of Xylella fastidiosa

• Author(s): Banks, D.; Chen, Jianchi; Jarret, R.; Jones, Jes?s;
• Abstract: The 16S-23S rDNA spacer of the type strain (ATCC 35879) of Xylella fastidiosa was amplified by PCR, cloned and sequenced. The spacer sequence contains two tRNA genes, one for tRNAala and the other tRNAile. Identical tRNA genes were also found in the 16S-23S spacer sequences of different pathogenic and geographical strains of X. fastidiosa retrieved from GenBank database. In this particular locus, the gene order of tRNAala and tRNAile is conserved among all the studied strains of Xylella and Xanthomonas, and different from those of other bacteria such as Pseudomonas and Escherichia. Sequence analysis showed that Xanthomonas is the most closely related genus. Digestions with both Bam HI and Hin dIII produced two hybridization bands when a cloned 16S rDNA sequence was used as a probe. Since the 16S rDNA sequence has no restriction sites of the two endonucleases, we concluded that the studied Pierces disease strain of X. fastidiosa has two highly similar rrn operons.
• Publication Date: Jun 2001
• Journal: Phytopathology