Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44
Antimonial compounds can be found as a toxic contaminant in the environment. Mechanisms of microbial Sb oxidation and its role in microbial tolerance are limited. Previously, we showed Comamonas testosteroni S44 to be resistant to multiple heavy metals and was able to oxidize the toxic antimonite [S...
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Frontiers Media S.A.
2015-12-01
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| Series: | Frontiers in Molecular Biosciences |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fmolb.2015.00070/full |
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| author | Hongliang eLiu Hongliang eLiu Weiping eZhuang Shengzhe eZhang Christopher eRensing Jun eHuang Jie eLi Gejiao eWang |
| author_facet | Hongliang eLiu Hongliang eLiu Weiping eZhuang Shengzhe eZhang Christopher eRensing Jun eHuang Jie eLi Gejiao eWang |
| author_sort | Hongliang eLiu |
| collection | DOAJ |
| description | Antimonial compounds can be found as a toxic contaminant in the environment. Mechanisms of microbial Sb oxidation and its role in microbial tolerance are limited. Previously, we showed Comamonas testosteroni S44 to be resistant to multiple heavy metals and was able to oxidize the toxic antimonite [Sb(III)] to the much less toxic antimonate [Sb(V)]. In this study, transposon mutagenesis was performed in C. testosteroni S44 to isolate genes responsible for Sb(III) resistance and oxidation. An insertion mutation into iscR, which regulates genes involved in the biosynthesis of Fe-S clusters, generated a strain called iscR-280. This mutant strain was complemented with a plasmid carrying iscR to generate strain iscR-280C. Compared to the wild type S44 and iscR-280C, strain iscR-280 showed lower resistance to Sb(III) and a lower Sb(III) oxidation rate. Strain iscR-280 also showed lower resistance to As(III), Cd(II), Cu(II) and H2O2. In addition, intracellular γ-glutamylcysteine ligase (γ-GCL) activity and glutathione (GSH) content were decreased in the mutated strain iscR-280. Real-time RT-PCR and lacZ fusion expression assay indicated that transcription of iscR and iscS was induced by Sb(III). Results of electrophoretic mobility shift assay (EMSA) and bacterial one-hybrid (B1H) system demonstrated a positive interaction between IscR and its promoter region. The diverse defective phenotypes and various expression patterns suggested a role for IscR in contributing to multi-metal(loid)s resistance and Sb(III) oxidation via Fe-S cluster biogenesis and oxidative stress protection. Bacterial Sb(III) oxidation is a detoxification reaction. |
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| language | English |
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| spelling | doaj.art-469c76bf86084beca8025a3bc29964232022-12-22T01:22:24ZengFrontiers Media S.A.Frontiers in Molecular Biosciences2296-889X2015-12-01210.3389/fmolb.2015.00070170329Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44Hongliang eLiu0Hongliang eLiu1Weiping eZhuang2Shengzhe eZhang3Christopher eRensing4Jun eHuang5Jie eLi6Gejiao eWang7Huazhong Agricultural UniversityShandong University of TechnologyHuazhong Agricultural UniversityHuazhong Agricultural UniversityUniversity of CopenhagenHuazhong Agricultural UniversityHuazhong Agricultural UniversityHuazhong Agricultural UniversityAntimonial compounds can be found as a toxic contaminant in the environment. Mechanisms of microbial Sb oxidation and its role in microbial tolerance are limited. Previously, we showed Comamonas testosteroni S44 to be resistant to multiple heavy metals and was able to oxidize the toxic antimonite [Sb(III)] to the much less toxic antimonate [Sb(V)]. In this study, transposon mutagenesis was performed in C. testosteroni S44 to isolate genes responsible for Sb(III) resistance and oxidation. An insertion mutation into iscR, which regulates genes involved in the biosynthesis of Fe-S clusters, generated a strain called iscR-280. This mutant strain was complemented with a plasmid carrying iscR to generate strain iscR-280C. Compared to the wild type S44 and iscR-280C, strain iscR-280 showed lower resistance to Sb(III) and a lower Sb(III) oxidation rate. Strain iscR-280 also showed lower resistance to As(III), Cd(II), Cu(II) and H2O2. In addition, intracellular γ-glutamylcysteine ligase (γ-GCL) activity and glutathione (GSH) content were decreased in the mutated strain iscR-280. Real-time RT-PCR and lacZ fusion expression assay indicated that transcription of iscR and iscS was induced by Sb(III). Results of electrophoretic mobility shift assay (EMSA) and bacterial one-hybrid (B1H) system demonstrated a positive interaction between IscR and its promoter region. The diverse defective phenotypes and various expression patterns suggested a role for IscR in contributing to multi-metal(loid)s resistance and Sb(III) oxidation via Fe-S cluster biogenesis and oxidative stress protection. Bacterial Sb(III) oxidation is a detoxification reaction.http://journal.frontiersin.org/Journal/10.3389/fmolb.2015.00070/fullOxidative Stressiron-sulfur clusterIscRComamonas testosteronemulti-metal resistanceantimonite oxidation |
| spellingShingle | Hongliang eLiu Hongliang eLiu Weiping eZhuang Shengzhe eZhang Christopher eRensing Jun eHuang Jie eLi Gejiao eWang Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44 Frontiers in Molecular Biosciences Oxidative Stress iron-sulfur cluster IscR Comamonas testosterone multi-metal resistance antimonite oxidation |
| title | Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44 |
| title_full | Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44 |
| title_fullStr | Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44 |
| title_full_unstemmed | Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44 |
| title_short | Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44 |
| title_sort | global regulator iscr positively contributes to antimonite resistance and oxidation in comamonas testosterone s44 |
| topic | Oxidative Stress iron-sulfur cluster IscR Comamonas testosterone multi-metal resistance antimonite oxidation |
| url | http://journal.frontiersin.org/Journal/10.3389/fmolb.2015.00070/full |
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