Metabolic alterations mediated by 2-ketobutyrate in Escherichia coli K12

Mol Gen Genet. 1984;193(3):473-8. doi: 10.1007/BF00382086.

Abstract

We have previously proposed that 2-ketobutyrate is an alarmone in Escherichia coli. Circumstantial evidence suggested that the target of 2-ketobutyrate was the phosphoenol pyruvate: glycose phosphotransferase system (PTS). We demonstrate here that the phosphorylated metabolites of the glycolytic pathway experience a dramatic downshift upon addition of 2-ketobutyrate (or its analogues). In particular, fructose-1,6-diphosphate, glucose-6-phosphate, fructose-6-phosphate and acetyl-CoA concentrations drop by a factor of 10, 3, 4, and 5 respectively. This result is consistent with (i) an inhibition of the PTS by 2-ketobutyrate, (ii) a control of metabolism by fructose-1,6-diphosphate. Since fructose-1,6-diphosphate is an activator of phosphoenol pyruvate carboxylase and of pyruvate kinase, the concentration of their common substrate, phosphoenol pyruvate, does not decrease in parallel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Butyrates / pharmacology*
  • Escherichia coli / drug effects*
  • Escherichia coli / metabolism
  • Glycolysis / drug effects
  • Kinetics
  • Phosphoenolpyruvate Sugar Phosphotransferase System / antagonists & inhibitors
  • Phosphorylation
  • Ribonucleotides / isolation & purification
  • Structure-Activity Relationship

Substances

  • Butyrates
  • Ribonucleotides
  • alpha-ketobutyric acid
  • Phosphoenolpyruvate Sugar Phosphotransferase System