The intracellular concentration of acetyl phosphate in Escherichia coli is sufficient for direct phosphorylation of two-component response regulators.
Acetyl phosphate, the intermediate of the AckA-Pta pathway, acts as a global signal in Escherichia coli. Although acetyl phosphate clearly signals through two-component response regulators, it remains unclear whether acetyl phosphate acts as a direct phospho donor or functions through an indirect mechanism. We used two-dimensional thin-layer chromatography to measure the relative concentrations of acetyl phosphate, acetyl coenzyme A, ATP, and GTP over the course of the entire growth curve. We estimated that the intracellular concentration of acetyl phosphate in wild-type cells reaches at least 3 mM, a concentration sufficient to activate two-component response regulators via direct phosphoryl transfer.
Klein
Adam H
AH
Department of Microbiology and Immunology, Loyola University Chicago, 2160 S. First Ave. Bldg. 105, Maywood, IL 60153, USA.
Shulla
Ana
A
Reimann
Sylvia A
SA
Keating
David H
DH
Wolfe
Alan J
AJ
D000105:Acetyl Coenzyme A / Q000032:analysis; D000255:Adenosine Triphosphate / Q000032:analysis; D002855:Chromatography, Thin Layer; D003593:Cytoplasm / Q000737:chemistry*; D004926:Escherichia coli / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000032:analysis; D010755:Organophosphates / Q000032:analysis* / Q000378:metabolism; D010766:Phosphorylation; D015398:Signal Transduction
D010755:Organophosphates; C011632:acetyl phosphate; D000105:Acetyl Coenzyme A; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate