title: Subunit δ is the key player for assembly of the H(+)-translocating unit of Escherichia coli F(O)F1 ATP synthase.
abstract: The ATP synthase (F(O)F1) of Escherichia coli couples the translocation of protons across the cytoplasmic membrane to the synthesis or hydrolysis of ATP. This nanomotor is composed of the rotor c10γε and the stator ab2α3β3δ. To study the assembly of this multimeric enzyme complex consisting of membrane-integral as well as peripheral hydrophilic subunits, we combined nearest neighbor analyses by intermolecular disulfide bond formation or purification of partially assembled F(O)F1 complexes by affinity chromatography with the use of mutants synthesizing different sets of F(O)F1 subunits. Together with a time-delayed in vivo assembly system, the results demonstrate that F(O)F1 is assembled in a modular way via subcomplexes, thereby preventing the formation of a functional H(+)-translocating unit as intermediate product. Surprisingly, during the biogenesis of F(O)F1, F1 subunit δ is the key player in generating stable F(O). Subunit δ serves as clamp between ab2 and c10α3β3γε and guarantees that the open H(+) channel is concomitantly assembled within coupled F(O)F1 to maintain the low membrane proton permeability essential for viability, a general prerequisite for the assembly of multimeric H(+)-translocating enzymes.
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Hilbers
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Eggers
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany.
authors.forename: Kamila
authors.initials: K
authors.lastname: Pradela
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Friedrich
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Herkenhoff-Hesselmann
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Becker
authors.affiliation: From the Department of Microbiology, University of Osnabrück, Barbarastrasse 11, D-49069 Osnabrück, Germany. Electronic address: deckers-hebestreit@biologie.uni-osnabrueck.de.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Deckers-Hebestreit
mesh_terms: D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D009154:Mutation; D021122:Protein Subunits / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D006180:Proton-Translocating ATPases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D021122:Protein Subunits; D006180:Proton-Translocating ATPases
keywords: ATP Synthase; Escherichia coli; F1Fo ATPase; H+-ATPase; Membrane Proteins; Protein Assembly; Protein Cross-linking