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H istidine phosphocarrier protein regulates pyruvate kinase A activity in response to glucose in V ibrio vulnificus
Author(s) -
Kim HeyMin,
Park YoungHa,
Yoon ChangKyu,
Seok YeongJae
Publication year - 2015
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12936
Subject(s) - pep group translocation , phosphoenolpyruvate carboxykinase , biology , pyruvate kinase , biochemistry , histidine , vibrio vulnificus , glycolysis , enzyme , phosphorylation , bacteria , genetics
Summary The bacterial phosphoenolpyruvate:sugar phosphotransferase system ( PTS ) consists of two general energy‐coupling proteins [enzyme I and histidine phosphocarrier protein ( HPr )] and several sugar‐specific enzyme IIs . Although, in addition to the phosphorylation‐coupled transport of sugars, various regulatory roles of PTS components have been identified in E scherichia coli , much less is known about the PTS in the opportunistic human pathogen V ibrio vulnificus . In this study, we have identified pyruvate kinase A ( PykA ) as a binding partner of HPr in V . vulnificus . The interaction between HPr and PykA was strictly dependent on the presence of inorganic phosphate, and only dephosphorylated HPr interacted with PykA . Experiments involving domain swapping between the PykAs of V . vulnificus and E . coli revealed the requirement for the C ‐terminal domain of V . vulnificus PykA for a specific interaction with V . vulnificus HPr . Dephosphorylated HPr decreased the K m of PykA for phosphoenolpyruvate by approximately fourfold without affecting V max . Taken together, these findings indicate that the V . vulnificus PTS catalyzing the first step of glycolysis stimulates the final step of glycolysis in the presence of glucose through the direct interaction of dephospho‐ HPr with the C ‐terminal domain of PykA .