Mas 5

Unless otherwise indicated, chemicals were purchased from Sigma-Aldrich. MAs(V) was obtained from Chem Service, Inc., West Chester, PA, respectively. MAs(V) was reduced as described (Reay & Asher, 1977 (link)).

Escherichia coli Stellar^™ (Clontech Laboratories, Mountain View, CA) (F–, endA1, supE44, thi-1, recA1, relA1, gyrA96 phoA, Φ80d lacZΔ M15, Δ(lacZYA-argF)U169, Δ(mrrhsdRMS-mcrBC), ΔmcrA, λ–) (ref) was used for plasmid DNA construction and replication. E. coli AW3110(DE3) (Δars::cam F⁻IN(rrn-rrnE) (Carlin et al., 1995 (link)) bearing two plasmids, pACYC184-ParsP-gfp and pBAD-SparsR was constructed for use as an MAs(III) biosensor. For most experiments cultures of E. coli bearing the indicated plasmids were grown aerobically in Luria-Bertani (LB) medium or M9 medium at 37 °C supplemented with 100 μg/ml ampicillin or 34 μg/ml chloramphenicol, as required (Sambrook et al., 1989 ). S. putrefaciens 200 was a gift from Flynn Picardal, Indiana University. Unless otherwise noted, cultures of S. putrefaciens were grown aerobically in Luria–Bertani (LB) medium or M9 medium at 30 °C with shaking. Bacterial growth was monitored by measuring the optical density at 600 nm (OD₆₀₀). Unless otherwise indicated, all reagents were purchased from Sigma-Aldrich. MAs(V) was obtained from Chem Service, Inc., West Chester, PA,. MAs(III) were reduced by the method of Reay and Asher (Reay & Asher, 1977 (link)).

Arsenicals and S-adenosyl-L-methionine (SAM) were purchased from Sigma-Aldrich. MAs(V) was obtained from Chem Service, Inc., West Chester, PA. MAs(III) was prepared as described (Reay and Asher, 1977 (link)). All reagents were analytical grade.