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The Xanthomonas RaxH-RaxR Two-Component Regulatory System Is Orthologous to the Zinc-Responsive Pseudomonas ColS-ColR
Valley Stewart1, Pamela C Ronald2
1Department of Microbiology & Molecular Genetics, University of California, Davis, CA 95616, USA.
Microorganisms
|August 7, 2021
Summary
The Pseudomonas ColS-ColR system, regulating lipid A remodeling, is orthologous to Xanthomonas RaxH-RaxR. This study clarifies nomenclature, recommending Rax, Vgr, and Det designations for Xanthomonas species to avoid confusion.
Area of Science:
- Microbiology
- Genomics
- Molecular Biology
Background:
- Accurate ortholog assignment is crucial for inferring gene function from genome sequences.
- The ColS-ColR two-component system in Pseudomonas regulates membrane functions, including lipid A remodeling, in response to metal ions.
- Several two-component systems in Xanthomonas (RaxH-RaxR, VgrS-VgrR, DetS-DetR) have been incorrectly annotated as ColS-ColR.
Purpose of the Study:
- To clarify the orthologous relationships between Pseudomonas ColS-ColR and Xanthomonas two-component systems.
- To resolve nomenclature confusion regarding the ColS-ColR system in Xanthomonas species.
- To identify the specific Xanthomonas two-component system involved in lipid A remodeling.
Main Methods:
- Comparative analysis of sensor periplasmic domain sequences of Pseudomonas ColS and Xanthomonas RaxH, VgrS, and DetS.
- Identification and analysis of genes located adjacent to the Xanthomonas raxRH locus.
- Bioinformatic prediction of enzyme functions encoded by these adjacent genes.
Main Results:
- Sequence comparison revealed conserved features, including a Glu-X-X-Glu metal ion-binding motif, between Pseudomonas ColS and Xanthomonas RaxH.
- Three genes adjacent to Xanthomonas raxRH were identified, predicted to encode lipid A remodeling enzymes: lipid A phosphoethanolamine transferase (EptA), lipid A 1-phosphatase (LpxE), and a lipid A glycosyl transferase (ArnT).
- These findings strongly support the orthology between Pseudomonas ColS-ColR and Xanthomonas RaxH-RaxR systems in regulating lipid A remodeling.
Conclusions:
- The Xanthomonas RaxH-RaxR system is the functional ortholog of the Pseudomonas ColS-ColR system, responsible for lipid A remodeling.
- The study recommends discontinuing the use of ColS and ColR nomenclature for Xanthomonas species.
- Consistent use of Rax, Vgr, and Det designations for Xanthomonas two-component systems is advised to prevent future annotation errors and improve clarity in research.
Keywords:
ColS-ColRRaxH-RaxRVgrS-VgrRXanthomonas oryzae pv. oryzaelipid A 1-phosphataselipid A phosphoethanolamine transferaselipid A remodelingMore Related Videos
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