Cd2+ sensitivity of met4Δ and met31Δ met32Δ strains. Serial dilutions of wild-type (WT, W303-1A), met28Δ (CC769-7D), met4Δ (CC849-1B), met31Δ (CC867-1C), met32Δ (CC845-1C) and met31Δ met32Δ (CC845-1A) strains were plated onto YNB minimal medium in the presence and absence of 20 μM Cd2+ and grown for 2 days.