Antimony, like arsenic, is a toxic metalloid widely distributed in the environment. Microbial detoxification of antimony has recently been identified. Here we describe a novel bacterial P_1B-type antimonite (Sb(III))-translocating ATPase from the antimony-mining bacterium Comamonas testosterone JL40 that confers resistance to Sb(III). In a comparative proteomics analysis of strain JL40, an operon (ant operon) was up-regulated by Sb(III). The ant operon includes three genes, antR, antC and antA. AntR belongs to the ArsR/SmtB family of metalloregulatory proteins that regulates expression of the ant operon. AntA belongs to the P_1B family of the P-type cation-translocating ATPases. It has both similarities to and differences from other members of the P_1B-1 subfamily and appears to be the first identified member of a distinct subfamily that we designate P_1B-8. Expression AntA in E. coli AW3110 (Δars) conferred resistance to Sb(III) and reduced the intracellular concentration of Sb(III) but not As(III) or other metals. Everted membrane vesicles from cells expressing antA accumulated Sb(III) but not As(III), where uptake in everted vesicles reflects efflux from cells. AntC is a small protein with a potential Sb(III) binding site, and co-expression of AntC with AntA increased resistance to Sb(III). We propose that AntC functions as an Sb(III) chaperone to AntA, augmenting Sb(III) efflux. The identification of a novel Sb(III)-translocating ATPase enhances our understanding of the biogeochemical cycling of environmental antimony by bacteria.

锑与砷一样，是一种广泛分布于环境中的有毒类金属。最近已经确定了锑的微生物解毒作用。在这里，我们描述了一种新的细菌 P _1B型锑矿 (Sb(III))-易位来自锑矿细菌Comamonas 睾酮JL40 的 ATP 酶，它赋予对 Sb(III) 的抗性。在菌株 JL40 的比较蛋白质组学分析中，操纵子（蚂蚁操纵子）被 Sb(III) 上调。蚂蚁操纵子包括三个基因antR 、antC和antA。AntR 属于调节蚂蚁操纵子表达的金属调节蛋白 ArsR/SmtB 家族。AntA属于P _1BP型阳离子转运ATP酶家族。_{它与 P 1B-1}亚科的其他成员既有相似之处，也有不同之处，并且似乎是我们称为 P _1B-8的不同亚科的第一个确定的成员。大肠杆菌AW3110 ( Δars ) 中的表达AntA赋予了对 Sb(III) 的抗性并降低了 Sb(III) 的细胞内浓度，但不降低 As(III) 或其他金属的浓度。来自表达antA的细胞的外翻膜囊泡积累的 Sb(III) 但不是 As(III)，其中外翻囊泡的摄取反映了细胞的流出。AntC 是一种具有潜在 Sb(III) 结合位点的小蛋白，AntC 与 AntA 的共表达增加了对 Sb(III) 的抗性。我们建议 AntC 作为 AntA 的 Sb(III) 伴侣，增加 Sb(III) 外流。一种新型 Sb(III) 转运 ATP 酶的鉴定增强了我们对细菌对环境锑的生物地球化学循环的理解。