8.A.8 The Phosphotransferase System HPr (HPr) Family
The HPr family consists of bacterial proteins, all of which function as phosphoryl transfer proteins. They are energy-coupling constituents of the phosphotransferase system (PTS) (TC #4.A.1-4.A.7) which catalyzes sugar uptake via a group translocation mechanism. HPr proteins are not known to be homologous to any non-PTS proteins. The E. coli genome encodes five HPr paralogues. The functions of several of these proteins are known. They function in PTS-related regulatory capacities.