Bacteriophage protein PEIP is a potent Bacillus subtilis enolase inhibitor

Enolase is a highly conserved enzyme that presents in all organisms capable of glycolysis or fermentation. Its immediate product phosphoenolpyruvate is essential for other important processes like peptidoglycan synthesis and the phosphotransferase system in bacteria. Therefore, enolase inhibitors are of great interest. Here, we report that Gp60, a phage-encoded enolase inhibitor protein (PEIP) of bacteriophage SPO1 for Bacillus subtilis, is an enolase inhibitor. PEIP-expressing bacteria exhibit growth attenuation, thinner cell walls, and safranin color in Gram staining owing to impaired peptidoglycan synthesis. We solve the structure of PEIP-enolase tetramer and show that PEIP disassembles enolase by disrupting the basic dimer unit. The structure reveals that PEIP does not compete for substrate binding but induces a cascade of conformational changes that limit accessibility to the enolase catalytic site. This phage-inspired disassembly of enolase represents an alternative strategy for the development of anti-microbial drugs.