Histidine phosphocarrier protein surface pot

computer-generated image of surface potential of histidine phosphocarrier protein HPR (PDB code: 1pch),a component of the phosphoenolpyruvate- dependent sugar phosphotransferase system (PTS), a major carbohydrate active-transport system responsible for transport of certain hexose substrates across the cytoplasmic membrane of bacteria and mycoplasmas. The imidazole group on His-15 at the active site of HPR accepts a multi-enzyme system (Enzyme I) and transfers it to various sugar-specific PTS permeases.