CopB and CopL protect against Cu toxicity in S. aureus.
A, chromosomal location of genes involved in Cu homeostasis in S. aureus USA300_FPR3757. The copB and copL genes are located in the ACME, adjacent to the SCCmecIV genetic element. Locus tags are provided below the genes. B, copA, copB, and copL gene products are required to protect against Cu toxicity. Top, WT (JMB1100) and ΔcopB (JMB7900) strains containing pEPSA5 or pEPSA5_copB are shown. Bottom, WT and ΔcopL (JMB7711) strains containing pEPSA5 or pEPSA5_copL are shown. Strains were serially diluted and spot-plated on chemically defined media with or without 50 μm Cu. C, overexpression of copB or copL results in increased Cu resistance in the S. aureus USA400 strain MW2. The S. aureus USA400 clone MW2, which lacks genome-encoded copB and copL, containing pEPSA5, pEPSA5_copB, or pEPSA_copL is shown. Strains were serially diluted and spot-plated on chemically defined media without or with 100 μm Cu.