SRNA-Xcc1 explained

sRNA-Xcc1 (small RNA identified from Xanthomonas campestris pv. campestris) is a family of trans-acting non-coding RNA (also known as small RNA).^{[1] [2]} Homologs of sRNA-Xcc1 are found in a few bacterial strains belonging to alpha-proteobacteria, beta-proteobacteria, gamma-proteobacteria, and delta-proteobacteria. In Xanthomonas campestris pv. campestris, sRNA-Xcc1 is encoded by an integron gene cassette and is under the positive control of the virulence regulators HrpG and HrpX.^{[3] [4]}

Origin and phylogenetic distribution

sRNA-Xcc1 is encoded by a gene cassette in the integron of Xanthomonas campestris pv. campestris and homologs of sRNA-Xcc1 are frequently found in integron gene cassettes cloned from uncultured bacterium,^[5] it is possible that sRNA-Xcc1 is originally captured by integrons from natural environments. sRNA-Xcc1 homologs are found in a few taxonomically far related strains across alpha-, beta- and gamma-proteobacteria but not in close related bacteria, implying that sRNA-Xcc1 is transferred via horizontal gene transfer (HGT). sRNA-Xcc1 homologous gene are found located on Tn5542, a transposon carried by the plasmid pHMT112, indicating that the horizontal transfer of sRNA-Xcc1 is realized by means of transposons and/or plasmids.^[6]

Potential biological function

The expression of sRNA-Xcc1 is under the positive control of the two important virulence regulators HrpG and HrpX of Xanthomonas campestris pv. campestris, indicating that sRNA-Xcc1 may be involved in the pathogenesis of the pathogen.

Notes and References

1. Chen XL . Tang DJ . Jiang RP . He YQ . Jiang BL . Lu GT . Tang JL . sRNA-Xcc1, an integron-encoded transposon- and plasmid-transferred trans-acting sRNA, is under the positive control of the key virulence regulators HrpG and HrpX of Xanthomonas campestris pathovar campestris. . RNA Biol . 8 . 6 . 947–53 . 2011 . 21941121 . 10.4161/rna.8.6.16690 . 3256417.
2. Schmidtke C, Findeiß S, Sharma CM, Kuhfuß J, Hoffmann S, Vogel J, etal . Genome-wide transcriptome analysis of the plant pathogen Xanthomonas identifies sRNAs with putative virulence functions. . Nucleic Acids Res . 2011 . 40. 5. 2020–2031. 22080557 . 10.1093/nar/gkr904 . 3300014 .
3. Wengelnik K . Van den Ackerveken G . Bonas U . HrpG, a key hrp regulatory protein of Xanthomonas campestris pv. vesicatoria is homologous to two-component response regulators. . Mol Plant Microbe Interact . 9 . 8 . 704–12 . 1996 . 8870269 . 10.1094/mpmi-9-0704.
4. Wengelnik K . Bonas U . HrpXv, an AraC-type regulator, activates expression of five of the six loci in the hrp cluster of Xanthomonas campestris pv. vesicatoria. . J Bacteriol . 178 . 12 . 3462–9 . 1996 . 10.1128/jb.178.12.3462-3469.1996 . 8655542 . 178114.
5. Gillings MR . Holley MP . Stokes HW . Holmes AJ . Integrons in Xanthomonas: a source of species genome diversity. . Proc Natl Acad Sci U S A . 102 . 12 . 4419–24 . 2005 . 15755815 . 10.1073/pnas.0406620102 . 555480. 2005PNAS..102.4419G . free .
6. Tan HM . Tang HY . Joannou CL . Abdel-Wahab NH . Mason JR . The Pseudomonas putida ML2 plasmid-encoded genes for benzene dioxygenase are unusual in codon usage and low in G+C content. . Gene . 130 . 1 . 33–9 . 1993 . 8344526 . 10.1016/0378-1119(93)90343-2.