Energy Coupling to Periplasmic Binding Protein-Dependent Transport Systems: Stoichiometry of ATP Hydrolysis during Transport in vivo

• Published in: Proceedings of the National Academy of Sciences - PNAS 1989-11, Vol.86 (21), p.8257-8261
• Main Authors: Mimmack, M. L., Gallagher, M. P., Pearce, S. R., Hyde, S. C., Booth, I. R., Higgins, C. F.
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; ATP; ATP-Binding Cassette Transporters; Betaine - metabolism; Betaines; Biochemistry; Biological and medical sciences; Biological Transport, Active; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell physiology; Chemotactic Factors - metabolism; Chemotaxis; Energy Metabolism; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli Proteins; Fundamental and applied biological sciences. Psychology; Genotype; Glycine - metabolism; Hydrolysis; Maltose - metabolism; Maltose-Binding Proteins; Membrane and intracellular transports; Membrane transport proteins; Molecular and cellular biology; Molecules; Monosaccharide Transport Proteins; Mutation; Periplasmic Binding Proteins; Phenotypes; Proline - metabolism; Protein metabolism; Stoichiometry; sugars
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.86.21.8257

Periplasmic binding protein-dependent transport systems mediate the accumulation of many diverse substrates in prokaryotic cells. Similar transport systems, including the P-glycoprotein responsible for multidrug resistance in human tumors, are also found in eukaryotes. The mechanism by which energy is coupled to the accumulation of substrate by these transport systems has been controversial. In this paper we demonstrate that ATP hydrolysis occurs in vivo concomitantly with transport. These data strongly suggest that ATP hydrolysis directly energizes substrate accumulation by these transport systems. The apparent stoichiometry is one to two molecules of ATP hydrolyzed per molecule of substrate transported.