title: Energy coupling to periplasmic binding protein-dependent transport systems: stoichiometry of ATP hydrolysis during transport in vivo.
abstract: 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.
authors.affiliation: Department of Biochemistry, University of Dundee, Scotland, United Kingdom.
authors.forename: M L
authors.initials: ML
authors.lastname: Mimmack
authors.forename: M P
authors.initials: MP
authors.lastname: Gallagher
authors.forename: S R
authors.initials: SR
authors.lastname: Pearce
authors.forename: S C
authors.initials: SC
authors.lastname: Hyde
authors.forename: I R
authors.initials: IR
authors.lastname: Booth
authors.forename: C F
authors.initials: CF
authors.lastname: Higgins
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001622:Betaine / Q000378:metabolism; D001693:Biological Transport, Active; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002630:Chemotactic Factors / Q000378:metabolism; D002633:Chemotaxis; D004734:Energy Metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005838:Genotype; D005998:Glycine / Q000378:metabolism; D006868:Hydrolysis; D008320:Maltose / Q000378:metabolism; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D009154:Mutation; D033902:Periplasmic Binding Proteins; D011392:Proline / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D002630:Chemotactic Factors; D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D033902:Periplasmic Binding Proteins; C461599:maltose transport system, E coli; D001622:Betaine; D008320:Maltose; D000255:Adenosine Triphosphate; D011392:Proline; D005998:Glycine