Fig. 1

Effects of copA and zntA deletions in E. coli on the metal selectivity of ArsR WT. The E. coli cell-based biosensors with ArsR WT as regulatory proteins were exposed to 5 µM metal(loid) ions including As(III), Cd(II), Ni(II), Hg(II), Pb(II), Zn(II), and Cu(II). The expression levels of eGFP upon metal(loid) exposure are represented as induction coefficient values. A E. coli-arsR, B E. coli-arsR/copA, and C E. coli-arsR/zntA were used as host cells for the biosensors