Molecular model (no labels) of histidine
phosphocarrier protein HPR (pdb code: 1poh)(ribbon
diagram, His-15 shown as ball-and-stick model, no
labels). 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. The His-15
at the active site of HPR accepts a multi-enzyme
system (Enzyme I) and transfers it to various
sugar- specific PTS permeases.
