Synergistic interaction of glyceraldehydes-3-phosphate dehydrogenase and ArsJ, a novel organoarsenical efflux permease, confers arsenate resistance.
Synergistic interaction of glyceraldehydes-3-phosphate dehydrogenase and ArsJ, a novel organoarsenical efflux permease, confers arsenate resistance.
复制标题
DOI：
10.1111/mmi.13371
复制
发表时间：
2016-06
影响因子：
3.6
通讯作者：
Rosen BP
中科院分区：
文献类型：
--
作者：
Chen J;Yoshinaga M;Garbinski LD;Rosen BP
微生物生物转化是砷生物地球循环的主要贡献者。与无机砷的转化同时，有机砷途径最近被认为是砷全球循环的重要组成部分。对砷酸盐的抗性的充分表征途径是与亚砷酸盐流出相结合的还原。在这里，我们描述了一种新的砷酸盐抗性途径，涉及一种不寻常的五价有机砷的生物合成和挤出。许多砷抗性（ars）操纵子有两个功能未知的基因，它们与这些操纵子相连。其中一种是gapdh，编码糖酵解酶3-磷酸甘油醛脱氢酶。另一个，arsJ，编码主要促进子超家族（MFS）蛋白。这两个基因是从铜绿假单胞菌的染色体上克隆出来的。当在大肠杆菌中同时表达而不是单独表达时，gapdh 和 arsJ 特异性地赋予对砷酸盐的抗性并减少 As(V) 的积累。在纯化的 GAPDH、D-甘油醛 3-磷酸 (G3P) 和 NAD+ 存在下，表达 arsJ 的细胞的外翻膜囊泡积累了 As(V)。 GAPDH 形成不稳定的有机砷 1-砷-3-磷酸甘油酸酯 (1As3PGA)。我们认为 ArsJ 是一种外排通透酶，可将 1As3PGA 从细胞中挤出，并迅速解离为 As(V) 和 3-磷酸甘油酸 (3PGA)，从而创建一条新的砷酸盐抗性途径。
Microbial biotransformations are major contributors to the arsenic biogeocycle. In parallel with transformations of inorganic arsenic, organoarsenicals pathways have recently been recognized as important components of global cycling of arsenic. The well-characterized pathway of resistance to arsenate is reduction coupled to arsenite efflux. Here, we describe a new pathway of arsenate resistance involving biosynthesis and extrusion of an unusual pentavalent organoarsenical. A number of arsenic resistance (ars) operons have two genes of unknown function that are linked in these operons. One, gapdh, encodes the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase. The other, arsJ, encodes a major facilitator superfamily (MFS) protein. The two genes were cloned from the chromosome of Pseudomonas aeruginosa. When expressed together, but not alone, in Escherichia coli, gapdh and arsJ specifically conferred resistance to arsenate and decreased accumulation of As(V). Everted membrane vesicles from cells expressing arsJ accumulated As(V) in the presence of purified GAPDH, D-glceraldehylde 3-phosphate (G3P) and NAD+. GAPDH forms the unstable organoarsenical 1-arseno-3-phosphoglycerate (1As3PGA). We propose that ArsJ is an efflux permease that extrudes 1As3PGA from cells, where it rapidly dissociates into As(V) and 3-phosphoglycerate (3PGA), creating a novel pathway of arsenate resistance.