Metabolic alterations mediated by 2-ketobutyrate in Escherichia coli K12

✍ Scribed by Danchin, A. ;Dondon, L. ;Daniel, J.

• Book ID: 104747710
• Publisher: Springer
• Year: 1984
• Tongue: English
• Weight: 742 KB
• Volume: 193
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00382086

✦ Synopsis

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.