title: An alternative role of FoF1-ATP synthase in Escherichia coli: synthesis of thiamine triphosphate.
abstract: In E. coli, thiamine triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free thiamine diphosphate (ThDP) and P(i), the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F(1) or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for F(o)F(1)-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, F(o)F(1)-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
authors: Unit of Bioenergetics and Cerebral Excitability, GIGA-Neurosciences, University of Liège, Liège, Belgium.
authors: Tiziana
authors: T
authors: Gigliobianco
authors: Marjorie
authors: M
authors: Gangolf
authors: Bernard
authors: B
authors: Lakaye
authors: Bastien
authors: B
authors: Pirson
authors: Christoph
authors: C
authors: von Ballmoos
authors: Pierre
authors: P
authors: Wins
authors: Lucien
authors: L
authors: Bettendorff
mesh_terms: D002952:Citric Acid Cycle; D004926:Escherichia coli / Q000378:metabolism*; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019289:Pyruvic Acid / Q000737:chemistry / Q000378:metabolism; D013838:Thiamine Triphosphate / Q000096:biosynthesis*
chemical_list: D013838:Thiamine Triphosphate; D019289:Pyruvic Acid; D006180:Proton-Translocating ATPases