The Metal Homeostasis Protein, Lsp, of Streptococcus pyogenes Is Necessary for Acquisition of Zinc and Virulence

BF Weston, A Brenot, MG Caparon - Infection and immunity, 2009 - Am Soc Microbiol
BF Weston, A Brenot, MG Caparon
Infection and immunity, 2009Am Soc Microbiol
ABSTRACT “Cluster 9” family lipoproteins function as ligand-binding subunits of ABC-type
transporters in maintaining transition metal homeostasis and have been implicated in the
virulence of several bacteria. While these proteins share high similarity, the specific metal
that they recognize and whether their role in virulence directly involves metal homeostasis
cannot be reliably predicted. We examined the cluster 9 protein Lsp of Streptococcus
pyogenes and found that specific deletion of lsp produced mutants highly attenuated in a …
Abstract
“Cluster 9” family lipoproteins function as ligand-binding subunits of ABC-type transporters in maintaining transition metal homeostasis and have been implicated in the virulence of several bacteria. While these proteins share high similarity, the specific metal that they recognize and whether their role in virulence directly involves metal homeostasis cannot be reliably predicted. We examined the cluster 9 protein Lsp of Streptococcus pyogenes and found that specific deletion of lsp produced mutants highly attenuated in a murine model of soft tissue infection. Under standard in vitro conditions, growth of the Lsp mutant was indistinguishable from that of the wild type, but growth was defective under zinc-limited conditions. The growth defect could be complemented by plasmids expressing wild-type Lsp but not Lsp engineered to lack its putative lipidation residue. Furthermore, Zn2+ but not Mn2+ rescued Lsp growth, implicating Zn2+ as the physiological ligand for Lsp. Mutation of residues in the putative Zn2+-binding pocket generated variants both hypo- and hyperresistant to zinc starvation, and both mutant classes displayed attenuated virulence. Together, these data suggest that Lsp is a ligand-binding component of an ABC-type zinc permease and that perturbation of zinc homeostasis inhibits the ability of S. pyogenes to cause disease in a zinc-limited host milieu.
American Society for Microbiology