ARSENIC EFFLUX GOVERNED BY THE ARSENIC RESISTANCE DETERMINANT OF STAPHYLOCOCCUS-AUREUS PLASMID PI258
ARSENIC EFFLUX GOVERNED BY THE ARSENIC RESISTANCE DETERMINANT OF STAPHYLOCOCCUS-AUREUS PLASMID PI258
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DOI：
10.1128/jb.175.11.3480-3485.1993
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发表时间：
1993-06-01
影响因子：
3.2
通讯作者：
SILVER, S
中科院分区：
文献类型：
--
作者：
BROER, S;JI, GY;SILVER, S
金黄色葡萄球菌质粒pI 258的抗砷操纵子通过主动外排机制确定降低As-73的净细胞摄取。亚砷酸盐从细胞中输出;细胞内的砷酸盐首先被还原为亚砷酸盐，然后被运输出细胞。抗性细胞表现出较低的积累As-73起源于砷酸盐和亚砷酸盐。主动流出负载亚砷酸盐的细胞需要的质粒确定的arsB基因的存在下。流出的砷起源为砷酸盐需要的arsC基因的存在下，并发生更迅速地加入arsB。抑制剂研究与S.负载亚砷酸盐的金黄色葡萄球菌显示亚砷酸盐流出是能量依赖性的，并且似乎由膜电位驱动。用（AsO 43-）-As-73负载细胞，观察到能量需要ATP，从而得出结论，ATP是砷酸盐还原所必需的。当葡萄球菌砷抗性决定簇克隆到大肠杆菌中时，还发现砷和亚砷酸盐的积累以及砷-73从负载砷的细胞中的流出降低。coli质粒R773 arsA基因（依赖亚砷酸盐的ATP酶决定簇）反式插入S. aureus基因arsB导致对砷的抗性增加。
The arsenic resistance operon of Staphylococcus aureus plasmid pI258 determined lowered net cellular uptake of As-73 by an active efflux mechanism. Arsenite was exported from the cells; intracellular arsenate was first reduced to arsenite and then transported out of the cells. Resistant cells showed lower accumulation of As-73 originating from both arsenate and arsenite. Active efflux from cells loaded with arsenite required the presence of the plasmid-determined arsB gene. Efflux of arsenic originating as arsenate required the presence of the arsC gene and occurred more rapidly with the addition of arsB. Inhibitor studies with S. aureus loaded with arsenite showed that arsenite efflux was energy dependent and appeared to be driven by the membrane potential. With cells loaded with (AsO43-)-As-73, a requirement for ATP for energy was observed, leading to the conclusion that ATP was required for arsenate reduction. When the staphylococcal arsenic resistance determinant was cloned into Escherichia coli, lowered accumulation of arsenate and arsenite and As-73 efflux from cells loaded with arsenate were also found. Cloning of the E. coli plasmid R773 arsA gene (the determinant of the arsenite-dependent ATPase) in trans to the S. aureus gene arsB resulted in increased resistance to arsenite.