Ni2+ -uptake in Pseudomonas putida strain S4: a possible role of Mg2+ -uptake pump

Journal of biosciences

V N Tripathi¹  S Srivastava1¹ 

[1] Department of Genetics, University of Delhi, South Campus, New Delhi 110 021, India$$

关键词: CorA;    Co(III)Hex;    metal uptake;    Mg2+;    Ni2+;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Essential metal ion homeostasis is based on regulated uptake of metal ions, both during its scarcity and abundance. Pseudomonas putida strain S4, a multimetal resistant bacterium, was employed to investigate Ni2+ entry into cells. It was observed that Mg2+ regulates the entry of Ni2+ and by this plays a protective role to minimize Ni2+ toxicity in this strain. This protection was evident in both growth as well as viability. Intracellular accumulation of Ni2+ varied in accordance with Mg2+ concentrations in the medium. It was hypothesized that Ni2+ enters the cell using a broad Mg2+ pump, i.e. the CorA system, as the CorA inhibitor, i.e. Co(III) Hex, also inhibits Ni2+ uptake. This led to the inference that Mg2+-based protection was basically due to competitive inhibition of Ni2+ uptake. We also show that Zn2+ can further regulate the entry of Ni2+.

【 授权许可】

Unknown