Functional and expression analysis of the metal-inducible dmeRF system from Rhizobium legumionosarum bv. viciae
| Autor: | Rosa-Isabel Prieto, José Manuel Palacios, Juan Imperial, Belén Brito, Laura Rubio-Sanz |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Rhizobiaceae
Operon Biología Mutant Microbial Sensitivity Tests Biology medicine.disease_cause Applied Microbiology and Biotechnology Rhizobium leguminosarum Microbiology 03 medical and health sciences Plant Microbiology Nickel Gene expression medicine Symbiosis Gene 030304 developmental biology 0303 health sciences Ecology 030306 microbiology Cupriavidus metallidurans Gene Expression Profiling Peas Membrane Transport Proteins food and beverages Cobalt biology.organism_classification Molecular biology Gene Deletion Transcription Factors Food Science Biotechnology Cation diffusion facilitator |
| Zdroj: | Applied And Environmental Microbiology, ISSN 0099-2240, 2013-08, Vol. 79 Archivo Digital UPM instname |
| Popis: | A gene encoding a homolog to the cation diffusion facilitator protein DmeF from Cupriavidus metallidurans has been identified in the genome of Rhizobium leguminosarum UPM791. The R. leguminosarum dmeF gene is located downstream of an open reading frame (designated dmeR ) encoding a protein homologous to the nickel- and cobalt-responsive transcriptional regulator RcnR from Escherichia coli . Analysis of gene expression showed that the R. leguminosarum dmeRF genes are organized as a transcriptional unit whose expression is strongly induced by nickel and cobalt ions, likely by alleviating the repressor activity of DmeR on dmeRF transcription. An R. leguminosarum dmeRF mutant strain displayed increased sensitivity to Co(II) and Ni(II), whereas no alterations of its resistance to Cd(II), Cu(II), or Zn(II) were observed. A decrease of symbiotic performance was observed when pea plants inoculated with an R. leguminosarum dmeRF deletion mutant strain were grown in the presence of high concentrations of nickel and cobalt. The same mutant induced significantly lower activity levels of NiFe hydrogenase in microaerobic cultures. These results indicate that the R. leguminosarum DmeRF system is a metal-responsive efflux mechanism acting as a key element for metal homeostasis in R. leguminosarum under free-living and symbiotic conditions. The presence of similar dmeRF gene clusters in other Rhizobiaceae suggests that the dmeRF system is a conserved mechanism for metal tolerance in legume endosymbiotic bacteria. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|