title: 2-Ketobutyrate: a putative alarmone of Escherichia coli.
abstract: 2-ketobutyrate is synthesized from threonine by threonine deaminase (dehydratase) in E. coli. The effects of 2-ketobutyrate as a regulatory metabolite were studied in vivo. 2-ketobutyrate was shown to inhibit the phosphoenolpyruvate (PEP): sugar phosphotransferase system resulting in aspartate starvation, elevation of ppGpp endogenous pools, and cessation of growth in E. coli grown in glucose and related carbon sources. Accordingly, we propose that 2-ketobutyrate might serve as an alarmone whose concentration precisely governs the shift from anaerobic growth to aerobic growth in E. coli. Such shifts are common phenomena among the Enterobacteriaceae.
mesh_terms: D000693:Anaerobiosis; D001224:Aspartic Acid / Q000378:metabolism; D002087:Butyrates / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D006159:Guanosine Tetraphosphate / Q000378:metabolism; D006880:Hydroxy Acids / Q000494:pharmacology; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship
chemical_list: D002087:Butyrates; D006880:Hydroxy Acids; D001224:Aspartic Acid; D006159:Guanosine Tetraphosphate; C009670:vinylglycolic acid; C005087:alpha-ketobutyric acid; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System