FIG. 2.

Lsp mutants are sensitive to zinc starvation. Growth of the wild type (WT) was compared to that of the Lsp deletion mutant (Lsp⁻) as well as to the Lsp⁻ strain complemented with a plasmid expressing either wild-type Lsp (pLsp) or Lsp modified to lack its putative lipidation residue (pLspC20A). Zinc starvation was imposed by the addition of increasing concentrations of TPEN as shown, and growth is presented relative to that of the wild type without vector cultured in the absence of TPEN or antibiotic (reference culture). To control for any zinc-independent effects on growth caused by maintenance of a plasmid, empty vector plasmid pABG5 (pVec) was introduced into the WT and Lsp⁻ strains and all cultures conducted in medium supplemented with chloramphenicol. The data reported represent the means and standard errors of the means derived from at least two independent experiments. Asterisks indicate P values of <0.05.