文献类型： 外文期刊

作者： Yu, Yanshuang ¹ ; Chen, Jichen ² ; Li, Yuanping ¹ ; Liang, Jinxuan ¹ ; Xie, Zhenchen ¹ ; Feng, Renwei ¹ ; Alwathnani, ¹ ;

作者机构： 1.Fujian Agr & Forestry Univ, Coll Resources & Environm, Inst Environm Microbiol, Fuzhou, Fujian, Peoples R China

2.Fujian Acad Agr Sci, Inst Soil & Fertilizer, Fuzhou, Peoples R China

3.King Saud Univ, Dept Bot & Microbiol, Riyadh, Saudi Arabia

4.Florida Int Univ, Herbert Wertheim Coll Med, Dept Cellular Biol & Pharmacol, Miami, FL 33199 USA

5.Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA

6.Southwest Forestry Univ, Coll Ecol & Environm, Inst Environm Remediat & Human Hlth, Kunming, Yunnan, Peoples R China

关键词： arsenite; antimonite; methylarsenite; MarR; transcriptional repressor; regulator; ArsV

期刊名称：APPLIED AND ENVIRONMENTAL MICROBIOLOGY （ 影响因子：4.792； 五年影响因子：5.26 ）

ISSN： 0099-2240

年卷期： 2021 年 87 卷 24 期

页码：

收录情况： SCI

摘要： In this study, comprehensive analyses were performed to determine the function of an atypical MarR homolog in Achromobacter sp. strain As-55. Genomic analyses of Achromobacter sp. As-55 showed that this marR is located adjacent to an arsV gene. ArsV is a flavin-dependent monooxygenase that confers resistance to the antibiotic methylarsenite [MAs(III)], the organoarsenic compound roxarsone(III) [Rox (III)], and the inorganic antimonite [Sb(III)]. Similar marR genes are widely distributed in arsenic-resistant bacteria. Phylogenetic analyses showed that these MarRs are found in operons predicted to be involved in resistance to inorganic and organic arsenic species, so the subfamily was named MarR(ars). MarR(ars) orthologs have three conserved cysteine residues, which are Cys36, Cys37, and Cys157 in Achromobacter sp. As-55, mutation of which compromises the response to MAs(III)/Sb(III). GFP-fluorescent biosensor assays show that AdMarR(ars) (MarR protein of Achromobacter deleyi As55) responds to trivalent As(III) and Sb(III) but not to pentavalent As(V) or Sb(V). The results of RT-qPCR assays show that arsV is expressed constitutively in a marR deletion mutant, indicating that marR represses transcription of arsV. Moreover, electrophoretic mobility shift assays (EMSAs) demonstrate that AdMarR(ars) binds to the promoters of both marR and arsV in the absence of ligands and that DNA binding is relieved upon binding of As(III) and Sb(III). Our results demonstrate that AdMarR(ars) is a novel As(III)/ Sb(III)-responsive transcriptional repressor that controls expression of arsV, which confers resistance to MAs(III), Rox(III), and Sb(III). AdMarR(ars) and its orthologs form a subfamily of MarR proteins that regulate genes conferring resistance to arsenic-containing antibiotics. IMPORTANCE In this study, a MarR family member, AdMarR(ars) was shown to regulate the arsV gene, which confers resistance to arsenic-containing antibiotics. It is a founding member of a distinct subfamily that we refer to as MarR(ars), regulating genes conferring resistance to arsenic and antimony antibiotic compounds. AdMarR(ars) was shown to be a repressor containing conserved cysteine residues that are required to bind As(III) and Sb (III), leading to a conformational change and subsequent derepression. Here we show that members of the MarR family are involved in regulating arsenic-containing compounds.