Binding mode of FBP to EI as predicted by MD simulations
Fructose-1,6-bisphosphate (FBP) binds at the magnesium binding site that is typically occupied by phosphoenolpyruvate (PEP) in the catalytic site of enzyme I (EI) of the phosphoenolpyruvate-protein phosphotransferase system. The two phosphate groups of FBP coordinated the cofactor Mg2+, forming an octahedron coordination system together with the negatively charged side chains of Glu431 and Asp455 of ptsI and surrounding water molecules.