Characterization of the 1-phosphohistidinyl residue in the phosphocarrier protein HPr of the phosphoenolpyruvate: sugar phosphotransferase system of Streptococcus faecalis.
The phosphocarrier protein HPr of the bacterial phosphoenolpyruvate:sugar phosphotransferase system contains 1-phosphohistidine at residue 15. This residue and the active site residue Arg-17 are conserved in HPrs isolated from both Gram-positive and -negative bacteria. The pH- and temperature-dependent hydrolysis of the 1-phosphohistidinyl residue in P-HPr from Streptococcus faecalis has been investigated. The results show that the hydrolysis properties are very similar to those previously reported for P-HPr from Escherichia coli. It was postulated that the unusual hydrolysis properties were due to the presence of a carboxyl group at the active site, and it is now known that in HPr from Escherichia coli the C-terminal residue Glu-85 is present. The results in this paper suggest that a similar carboxyl group is present at the active site in HPr from Streptococcus faecalis.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000302:isolation & purification / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D013045:Species Specificity; D013816:Thermodynamics
D001426:Bacterial Proteins; D010761:Phosphorus Radioisotopes; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr