Comamonas testosteroni antA encodes an antimonite-translocating P-type ATPase

• Published in: The Science of the total environment 2021-02, Vol.754, p.142393-142393, Article 142393
• Main Authors: An, Lijin, Luo, Xiong, Wu, Minghan, Feng, Liling, Shi, Kaixiang, Wang, Gejiao, Rosen, Barry P., Li, Mingshun
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases - genetics; ant operon; Antimonite efflux; Antimonite-translocating ATPase; Antimony - metabolism; Comamonas testosterone; Comamonas testosteroni - metabolism; Escherichia coli - metabolism; P-type ATPases
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.142393

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 P1B-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 P1B family of the P-type cation-translocating ATPases. It has both similarities to and differences from other members of the P1B-1 subfamily and appears to be the first identified member of a distinct subfamily that we designate P1B-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. [Display omitted] •The ant operon is specifically induced by Sb(III).•AntA specifically confers the resistance to Sb(III).•AntA is a new subclass of ATPases named as P1B-8.•The ant-operon is the first report to specifically detoxify Sb(III) in bacteria.