The genome of the non-cultured, bacterial-like organism associated with citrus greening disease contains thenusG-rplKAJL-rpoBC gene cluster and the gene for a bacteriophage type DNA polymerase

Abstract

We have recently cloned three DNA fragments (In-2.6, In-1.0, and In-0.6) of the non-cultured, bacterial-like organism (BLO) associated with citrus greening disease. Nucleotide sequence determination has shown that fragment In-2.6 is part of the rplKAJL-rpoBC gene cluster, a well-known operon in eubacteria. The DNA fragment upstream of and partially overlapping with In-2.6 could be isolated and was shown to be the nusG gene. In Escherichia coli, nusG is also immediately upstream of rplKAJL-rpoBC. Fragment In-1.0 carries the gene for a bacteriophage type DNA polymerase. Fragment In-0.6 could not be identified. When In-2.6 was used, at high stringency, as a probe to detect greening BLO strains in infected plants, hybridization was obtained with all Asian strains tested, but not with the African strain examined. At lower stringencies, In-2.6 was able to detect also the African strain. The implications of these results in the taxonomical position of the greening BLO are discussed.

The tufB-secE-nusG-rplKAJL-rpoB gene cluster of the liberibacters: sequence comparisons, phylogeny and speciation

“…The b operon sequence of 'Ca. L. asiaticus' is known for an Indian strain (Poona strain) (Villechanoux et al, 1993) and a Japanese strain (GenBank accession no. AY342001).…”

“…L. asiaticus' (GenBank accession no. EU078703), the sequences of an Indian strain (M94319; Villechanoux et al, 1992Villechanoux et al, , 1993 and a Japanese strain (AY342001; Okuda et al, 2005) being already known. Finally, the b operon sequence of 'Ca.…”

“…L. asiaticus' (Villechanoux et al, 1992(Villechanoux et al, , 1993. Next, DNA from periwinkle plants infected with the Nelspruit strain (South Africa) of 'Ca.…”

Genomic characterization of a liberibacter present in an ornamental rutaceous tree, Calodendrum capense, in the Western Cape Province of South Africa. Proposal of 'Candidatus Liberibacter africanus subsp. capensis'.

“…Sequence of the PCR fragment amplified with primers 1897/1898 from the C. capense liberibacter Primers 1897\1898, originally designed on the sequence of the rplKAJL-rpoBC operon of ' Candidatus Liberibacter asiaticus ' (Planet et al, 1995, Villechanoux et al, 1993 allowed amplification of a 1n7 kbp fragment of the equivalent operon of ' Candidatus Liberibacter africanus '. This fragment comprises, at the 5h end, the intergenic region between ribosomal proteins A and J and, at the 3h end, the intergenic region between the ribosomal protein L and the β subunit of RNA polymerase (Villechanoux et al, 1993).…”

“…This fragment comprises, at the 5h end, the intergenic region between ribosomal proteins A and J and, at the 3h end, the intergenic region between the ribosomal protein L and the β subunit of RNA polymerase (Villechanoux et al, 1993). When used to amplify DNA extracted …”