FIG 5.

(A) ZnuA under metal limitation conditions could not be replaced by the periplasmic zinc-binding proteins ZinT and TroA. The TCZA15 (troC::Gm znuA::Km) strain was complemented with functional znuA, zinT, or troA from the plasmids pZNUA, pZINT, and pTROA, respectively. The cells were tested on plates containing LA (rich medium) and AB (minimal medium). Sensitivity to EDTA on AB plates containing EDTA (0.3, 0.6, 0.9, and 1.2 mM) was assessed as described for Fig. 3. (B) ZinT could not function when TroCBA was inactivated. The PC135 (zinT::Gm) and TCZT14 (troC::Gm zinT::Km) strains were complemented with functional zinT from the plasmid pZINT. (C) Important role of zinc chaperones ZinT and YciC. The ZTYC15 (zinT::Gm yciC::Km) strain was complemented with functional zinT or yciC from the plasmids pZINT and pYCIC, respectively.