Enzyme I facilitates reverse flux from pyruvate to phosphoenolpyruvate in Escherichia coli.

ABSTRACT: The 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

SUBMITTER: Long CP 

PROVIDER: S-EPMC5290146 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature