Sato T, Kobayashi Y
Department of Applied Biological Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan.
J Bacteriol. 1998 Apr;180(7):1655-61. doi: 10.1128/JB.180.7.1655-1661.1998.
The Bacillus subtilis skin element confers resistance to arsenate and arsenite. The ars operon in the skin element contains four genes in the order arsR, ORF2, arsB, and arsC. Three of these genes are homologous to the arsR, arsB, and arsC genes from the staphylococcal plasmid pI258, while no homologs of ORF2 have been found. Inactivation of arsR, arsB, or arsC results in either constitutive expression of ars, an arsenite- and arsenate-sensitive phenotype, or an arsenate-sensitive phenotype, respectively. These results suggest that ArsR, ArsB, and ArsC function as a negative regulator, a membrane-associated protein need for extrusion of arsenite, and arsenate reductase, respectively. Expression of the ars operon was induced by arsenate, arsenite, and antimonite. Northern hybridization and primer extension analysis showed that synthesis of a full-length ars transcript of about 2.4 kb was induced by arsenate and that the ars promoter contains sequences that resemble the -10 and -35 regions of promoters that are recognized by E sigmaA.
枯草芽孢杆菌的皮肤元件赋予对砷酸盐和亚砷酸盐的抗性。皮肤元件中的ars操纵子包含四个基因，顺序为arsR、ORF2、arsB和arsC。其中三个基因与葡萄球菌质粒pI258中的arsR、arsB和arsC基因同源，而未发现ORF2的同源物。arsR、arsB或arsC的失活分别导致ars的组成型表达、对亚砷酸盐和砷酸盐敏感的表型或对砷酸盐敏感的表型。这些结果表明，ArsR、ArsB和ArsC分别作为负调节因子、亚砷酸盐外排所需的膜相关蛋白和砷酸盐还原酶发挥作用。ars操纵子的表达由砷酸盐、亚砷酸盐和锑酸盐诱导。Northern杂交和引物延伸分析表明，约2.4 kb的全长ars转录本的合成由砷酸盐诱导，且ars启动子包含类似于被E sigmaA识别的启动子的-10和-35区域的序列。
