Open AccessDual phosphorylation of Mycoplasma pneumoniae HPr by Enzyme I and HPr kinase suggests an extended phosphoryl group susceptibility of HPr
Author(s) -
Halbedel Sven,
Stülke Jörg
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.05.004
Subject(s) - pep group translocation , phosphorylation , kinase , biochemistry , enzyme , phosphotransferase , bacillus subtilis , biology , mycoplasma pneumoniae , phosphorylation cascade , protein phosphorylation , chemistry , protein kinase a , phosphoenolpyruvate carboxykinase , bacteria , genetics , history , archaeology , pneumonia
In Gram‐positive bacteria, the HPr protein of the phosphoenolpyruvate:sugar phosphotransferase system can be phosphorylated at two distinct sites, His‐15 and Ser‐46. While the former phosphorylation is implicated in phosphoryl transfer to the incoming sugars, the latter serves regulatory purposes. In Bacillus subtilis , the two phosphorylation events are mutually exclusive. In contrast, doubly phosphorylated HPr is present in cell extracts of Mycoplasma pneumoniae . In this work, we studied the ability of the two single phosphorylated HPr species to accept a second phosphoryl group. Indeed, both Enzyme I and the HPr kinase/phosphorylase from M. pneumoniae are able to use phosphorylated HPr as a substrate. The formation of doubly phosphorylated HPr is substantially slower as compared to the phosphorylation of free HPr. However, the rate of formation of doubly phosphorylated HPr is sufficient to account for the amount of HPr(His?P)(Ser‐P) detected in M. pneumoniae cells.