Histidine phosphocarrier protein,surface pot

Computer-generated image of surface potential of histidine phospho-carrier protein HPR (pdb code: 1poh) (His-15 shown as ball-and-stick model). HPR is part of the phosphoenolpyruvate-dependent sugar phospho- transferase system (PTS), a major carbohydrate active transport system moving certain hexoses across the cytoplasmic membrane of bacteria and mycoplasmas. His-15 at active site of HPR accepts a multi-enzyme system (Enzyme I) and transfers it to various sugar-specific PTS permeases.