DUAL-MODE OF ENERGY COUPLING BY THE OXYANION-TRANSLOCATING ARSB PROTEIN
DUAL-MODE OF ENERGY COUPLING BY THE OXYANION-TRANSLOCATING ARSB PROTEIN
复制标题
DOI：
10.1128/jb.177.2.385-389.1995
复制
发表时间：
1995-01-01
影响因子：
3.2
通讯作者：
ROSEN, BP
中科院分区：
文献类型：
--
作者：
DEY, S;ROSEN, BP
R-因子R773的ars操纵子的arsA和arsB基因通过编码阴离子转运ATP酶赋予大肠杆菌对砷的抗性。在表达arsA和arsB基因的细胞和仅表达arsB基因的细胞中比较了砷的抗性和砷转运的体内能量学。与同时表达arsA和arsB基因的细胞相比，表达arsB基因的细胞表现出中等的砷抗性。这两种类型的细胞表现出能量依赖性亚砷酸盐排斥。从仅表达arsB基因的细胞中排除（AsO 2-）-As-73与电化学能偶联，而在同时表达两种基因的细胞中，转运与化学能偶联，最有可能是ATP。这些结果表明，Ars阴离子转运系统可以是一个强制性的ATP耦合的初级泵或二级载体耦合到质子动力，这取决于运输复合物的亚基组成。
The arsA and arsB genes of the ars operon of R-factor R773 confer arsenite resistance in Escherichia coli by coding for an anion-translocating ATPase. Arsenite resistance and the in vivo energetics of arsenite transport were compared in cells expressing the arsA and arsB genes and those expressing just the arsB gene. Cells expressing the arsB gene exhibited intermediate arsenite resistance compared with tells expressing both the arsA and arsB genes. Both types of cells exhibited energy-dependent arsenite exclusion. Exclusion of (AsO2-)-As-73 from cells expressing only the arsB gene was coupled to electrochemical energy, while in cells expressing both genes, transport was coupled to chemical energy, most likely ATP. These results suggest that the Ars anion transport system can be either an obligatory ATP-coupled primary pump or a secondary carrier coupled to the proton motive force, depending on the subunit composition of the transport complex.