An acpXL Mutant of Rhizobium leguminosarum bv. phaseoli Lacks 27-Hydroxyoctacosanoic Acid in Its Lipid A and Is Developmentally Delayed during Symbiotic Infection of the Determinate Nodulating Host Plant Phaseolus vulgaris
| Autor: | Dusty B. Brown, D. Janine Sherrier, Elmar L. Kannenberg, Yu-Chu Huang, Russell W. Carlson |
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| Rok vydání: | 2011 |
| Předmět: |
Chromatography
Gas Detergents Mutant medicine.disease_cause Microbiology Legionella pneumophila Mass Spectrometry Rhizobium leguminosarum Lipid A Plant Microbiology Bacterial Proteins Acyl Carrier Protein medicine Symbiosis Molecular Biology Polymyxin B Phaseolus Virulence biology food and beverages Sodium Dodecyl Sulfate biology.organism_classification Anti-Bacterial Agents Microscopy Electron Acyl carrier protein Symbiosome biology.protein Hydroxy Acids Bacteria Deoxycholic Acid |
| Zdroj: | Journal of Bacteriology. 193:4766-4778 |
| ISSN: | 1098-5530 0021-9193 |
| Popis: | Rhizobium leguminosarum is a Gram-negative bacterium that forms nitrogen-fixing symbioses with compatible leguminous plants via intracellular invasion and establishes a persistent infection within host membrane-derived subcellular compartments. Notably, an unusual very-long-chain fatty acid (VLCFA) is found in the lipid A of R. leguminosarum as well as in the lipid A of the medically relevant pathogens Brucella abortus , Brucella melitensis , Bartonella henselae , and Legionella pneumophila , which are also able to persist within intracellular host-derived membranes. These bacterial symbionts and pathogens each contain a homologous gene region necessary for the synthesis and transfer of the VLCFA to the lipid A. Within this region lies a gene that encodes the specialized acyl carrier protein AcpXL, on which the VLCFA is built. This study describes the biochemical and infection phenotypes of an acpXL mutant which lacks the VLCFA. The mutation was created in R. leguminosarum bv. phaseoli strain 8002, which forms symbiosis with Phaseolus vulgaris , a determinate nodulating legume. Structural analysis using gas chromatography and mass spectrometry revealed that the mutant lipid A lacked the VLCFA. Compared to the parent strain, the mutant was more sensitive to the detergents deoxycholate and dodecyl sulfate and the antimicrobial peptide polymyxin B, suggesting a compromise to membrane stability. In addition, the mutant was more sensitive to higher salt concentrations. Passage through the plant restored salt tolerance. Electron microscopic examination showed that the mutant was developmentally delayed during symbiotic infection of the host plant Phaseolus vulgaris and produced abnormal symbiosome structures. |
| Databáze: | OpenAIRE |
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