Role of ArsEFG in Roxarsone and Nitarsone Detoxification and Resistance
Role of ArsEFG in Roxarsone and Nitarsone Detoxification and Resistance
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ArsEFG 在洛克沙胂和硝胂解毒和耐药中的作用
DOI：
10.1021/acs.est.9b01187
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发表时间：
2019-06-04
影响因子：
11.4
通讯作者：
Rosen, Barry P.
中科院分区：
文献类型：
--
作者：
Chen, Jian;Zhang, Jun;Rosen, Barry P.
有机砷生物转化是砷全球循环的重要组成部分。 Roxarson（3-硝基-4-羟基苯砷酸盐或 Rox(V)）和硝胂松（4-硝基苯砷酸盐或 Nit(V)）是合成芳香族有机砷，在家禽业中用作添加剂，以预防球虫病并提高饲料效率。在这里，我们描述了一种抵抗洛克沙胂和硝胂的新途径，涉及将其三价形式（Rox（III））和（Nit（III））生物转化为三价有机砷化合物HAPA（III）和pAsA（III），并与从细胞中主动挤出芳香族氨基苯甲基胂化合物相结合。 arsE、arsF 和 arsG 是从腐烂希瓦氏菌 200 染色体中的砷岛克隆出来的。当在大肠杆菌中一起而非单独表达时，arsEFG 赋予对 Rox(III) 和 Nit(III) 的抗性，并减少两者的积累。细胞通过将硝基还原为胺，将 Rox(III) 或 Nit(III) 转化为 HAPA(III) 或 pAsA(III)。表达 arsG 的细胞外翻的膜囊泡积累了 HAPA(III) 或 pAsA(III)。我们的数据表明，ass 和 ArsF 一起将 Rox(III) 或 Nit(III) 还原为 HAPA(III) 或 pAsA(III)，后者通过外排渗透酶 ArsG 从细胞中挤出。 ArsE、ArsF 和 ArsG 催化耦合途径的鉴定是对洛克沙胂和硝胂抗性的新途径的分子描述。
Organoarsenical biotransformations are important components of the global cycling of arsenic. Roxarsone (3-nitro-4-hydroxybenzenearsenate or Rox(V)) and nitarsone (4-nitrobenzene arsenate or Nit(V)) are synthetic aromatic organoarsenicals used in the poultry industry as additives to prevent coccidiosis and improve feed efficiency. Here, we describe a novel pathway of resistance to roxarsone and nitarsone involving biotransformation of their trivalent forms (Rox(III)) and (Nit(III)) to the trivalent organoarsenicals HAPA(III) and pAsA(III), coupled to active extrusion of the aromatic amino-benezylarsenicals from the cells. The arsE, arsF, and arsG were cloned from the arsenic island in the chromosome of Shewanella putrefaciens 200. When expressed in Escherichia coli together, but not alone, arsEFG conferred resistance to Rox(III) and Nit(III) and decreased the accumulation of both. The cells transformed Rox(III) or Nit(III) to HAPA(III) or pAsA(III) by reducing the nitro group to an amine. Everted membrane vesicles from cells expressing arsG accumulated HAPA(III) or pAsA(III). Our data indicate that ArsE and ArsF together reduce Rox(III) or Nit(III) to HAPA(III) or pAsA(III), which are extruded from the cells by the efflux permease ArsG. Identification of the coupled pathway of ArsE, ArsF, and ArsG catalysis is a molecular description of a novel pathway for resistance to roxarsone and nitarsone.