A Small-Molecule Inhibitor of Iron-Sulfur Cluster Assembly Uncovers a Link between Virulence Regulation and Metabolism in Staphylococcus aureus

Cell Chem Biol. 2016 Nov 17;23(11):1351-1361. doi: 10.1016/j.chembiol.2016.09.012. Epub 2016 Oct 20.

Abstract

The rising problem of antimicrobial resistance in Staphylococcus aureus necessitates the discovery of novel therapeutic targets for small-molecule intervention. A major obstacle of drug discovery is identifying the target of molecules selected from high-throughput phenotypic assays. Here, we show that the toxicity of a small molecule termed '882 is dependent on the constitutive activity of the S. aureus virulence regulator SaeRS, uncovering a link between virulence factor production and energy generation. A series of genetic, physiological, and biochemical analyses reveal that '882 inhibits iron-sulfur (Fe-S) cluster assembly most likely through inhibition of the Suf complex, which synthesizes Fe-S clusters. In support of this, '882 supplementation results in decreased activity of the Fe-S cluster-dependent enzyme aconitase. Further information regarding the effects of '882 has deepened our understanding of virulence regulation and demonstrates the potential for small-molecule modulation of Fe-S cluster assembly in S. aureus and other pathogens.

Keywords: SaeRS; Staphylococcus; aconitase; fermentation; iron-sulfur cluster; virulence factors.

MeSH terms

  • Aconitate Hydratase / metabolism
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / metabolism*
  • Drug Discovery
  • Humans
  • Iron-Sulfur Proteins / metabolism*
  • Protein Kinases / metabolism
  • Signal Transduction / drug effects
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology*
  • Staphylococcal Infections / drug therapy*
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / growth & development
  • Staphylococcus aureus / metabolism
  • Transcription Factors / metabolism
  • Virulence / drug effects
  • Virulence Factors / metabolism*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Iron-Sulfur Proteins
  • SaeR protein, Staphylococcus aureus
  • Small Molecule Libraries
  • Transcription Factors
  • Virulence Factors
  • Protein Kinases
  • SaeS protein, Staphylococcus aureus
  • Aconitate Hydratase