Browsing by Author "Gebreselassie, Nikodimos A"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
Item Enzyme I facilitates reverse flux from pyruvate to phosphoenolpyruvate in Escherichia coli(Nature Publishing Group, 2017-01-27) Long, Christopher P; Au, Jennifer; Sandoval, Nicholas R; Gebreselassie, Nikodimos A; Antoniewicz, Maciek R; Christopher P. Long; Jennifer Au; Nicholas R. Sandoval; Nikodimos A. Gebreselassie; Maciek R. Antoniewicz; Antoniewicz, Maciej RobertThe bacterial phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) consists of cascading phosphotransferases that couple the simultaneous import and phosphorylation of a variety of sugars to the glycolytic conversion of phosphoenolpyruvate (PEP) to pyruvate. As the primary route of glucose uptake in E. coli, the PTS plays a key role in regulating central carbon metabolism and carbon catabolite repression, and is a frequent target of metabolic engineering interventions. Here we show that Enzyme I, the terminal phosphotransferase responsible for the conversion of PEP to pyruvate, is responsible for a significant in vivo flux in the reverse direction (pyruvate to PEP) during both gluconeogenic and glycolytic growth. We use 13C alanine tracers to quantify this back-flux in single and double knockouts of genes relating to PEP synthetase and PTS components. Our findings are relevant to metabolic engineering design and add to our understanding of gene-reaction connectivity in E. coli.