Octameric structure ofStaphylococcus aureusenolase in complex with phosphoenolpyruvate

Abstract

Staphylococcus aureusis a Gram-positive bacterium with strong pathogenicity that causes a wide range of infections and diseases. Enolase is an evolutionarily conserved enzyme that plays a key role in energy production through glycolysis. Additionally, enolase is located on the surface ofS. aureusand is involved in processes leading to infection. Here, crystal structures ofSa_enolase with and without bound phosphoenolpyruvate (PEP) are presented at 1.6 and 2.45 Å resolution, respectively. The structure reveals an octameric arrangement; however, both dimeric and octameric conformations were observed in solution. Furthermore, enzyme-activity assays show that only the octameric variant is catalytically active. Biochemical and structural studies indicate that the octameric form ofSa_enolase is enzymatically activein vitroand likely alsoin vivo, while the dimeric form is catalytically inactive and may be involved in other biological processes.