farnesyl-pyrophosphate and Staphylococcal-Infections

3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, a mevalonate synthetase, is required for the growth of Staphylococcus aureus. However, the essential role of the enzyme in cell growth has remained unclear. Here we show that three mutants possessed single-base substitutions in the mvaA gene, which encodes HMG-CoA reductase, show a temperature-sensitive phenotype. The phenotype was suppressed by the addition of mevalonate or farnesyl diphosphate, which is a product synthesized from mevalonate. Farnesyl diphosphate is a precursor of undecaprenyl phosphate that is required for peptidoglycan synthesis. The rate of peptidoglycan synthesis was decreased in the mvaA mutants under the non-permissive conditions and the phenotype was suppressed by the addition of mevalonate. HMG-CoA reductase activities of mutant MvaA proteins in the temperature sensitive mutants were lower than that of wild-type MvaA protein. Our findings from genetic and biochemical analyses suggest that mevalonate produced by HMG-CoA reductase is required for peptidoglycan synthesis for S. aureus cell growth.

Topics: Cell Cycle; Enzyme Stability; Humans; Hydroxymethylglutaryl CoA Reductases; Mevalonic Acid; Peptidoglycan; Polyisoprenyl Phosphates; Sesquiterpenes; Staphylococcal Infections; Staphylococcus aureus; Temperature

Staphylococcus aureus produces hospital- and community-acquired infections, with methicillin-resistant S. aureus posing a serious public health threat. The golden carotenoid pigment of S. aureus, staphyloxanthin, promotes resistance to reactive oxygen species and host neutrophil-based killing, and early enzymatic steps in staphyloxanthin production resemble those for cholesterol biosynthesis. We determined the crystal structures of S. aureus dehydrosqualene synthase (CrtM) at 1.58 angstrom resolution, finding structural similarity to human squalene synthase (SQS). We screened nine SQS inhibitors and determined the structures of three, bound to CrtM. One, previously tested for cholesterol-lowering activity in humans, blocked staphyloxanthin biosynthesis in vitro (median inhibitory concentration approximately 100 nM), resulting in colorless bacteria with increased susceptibility to killing by human blood and to innate immune clearance in a mouse infection model. This finding represents proof of principle for a virulence factor-based therapy against S. aureus.

Topics: Amino Acid Sequence; Animals; Anti-Bacterial Agents; Bacterial Proteins; Cell Line; Cell Proliferation; Cholesterol; Crystallography, X-Ray; Enzyme Inhibitors; Farnesyl-Diphosphate Farnesyltransferase; Humans; Mice; Molecular Sequence Data; Organothiophosphorus Compounds; Polyisoprenyl Phosphates; Protein Structure, Secondary; Sesquiterpenes; Staphylococcal Infections; Staphylococcus aureus; Virulence; Xanthophylls