ATP Synthase b Subunit Dimerization Domain

Experimental Data Snapshot

  • Resolution: 1.55 Å
  • R-Value Free: 0.313 
  • R-Value Work: 0.282 
  • R-Value Observed: 0.285 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


The "second stalk" of Escherichia coli ATP synthase: structure of the isolated dimerization domain.

Del Rizzo, P.A.Bi, Y.Dunn, S.D.Shilton, B.H.

(2002) Biochemistry 41: 6875-6884

  • DOI: https://doi.org/10.1021/bi025736i
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The b subunit of E. coli F(0)F(1)-ATPase links the peripheral F(1) subunits to the membrane-integral F(0) portion and functions as a "stator", preventing rotation of F(1). The b subunit is present as a dimer in ATP synthase, and residues 62-122 are required to mediate dimerization. To understand how the b subunit dimer is formed, we have studied the structure of the isolated dimerization domain, b(62-122). Analytical ultracentrifugation and solution small-angle X-ray scattering (SAXS) indicate that the b(62-122) dimer is extremely elongated, with a frictional ratio of 1.60, a maximal dimension of 95 A, and a radius of gyration of 27 A, values that are consistent with an alpha-helical coiled-coil structure. The crystal structure of b(62-122) has been solved and refined to 1.55 A. The protein crystallized as an isolated, monomeric alpha helix with a length of 90 A. Combining the crystal structure of monomeric b(62-122) with SAXS data from the dimer in solution, we have constructed a model for the b(62-122) dimer in which the two helices form a coiled coil with a right-handed superhelical twist. Analysis of b sequences from E. coli and other prokaryotes indicates conservation of an undecad repeat, which is characteristic of a right-handed coiled coil and consistent with our structural model. Mutation of residue Arg-83, which interrupts the undecad pattern, to alanine markedly stabilized the dimer, as expected for the proposed two-stranded, right-handed coiled-coil structure.

  • Organizational Affiliation

    Department of Biochemistry, University of Western Ontario, London, ON N6A 5C1, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ATP Synthase B Chain61Escherichia coliMutation(s): 0 
Find proteins for P0ABA0 (Escherichia coli (strain K12))
Explore P0ABA0 
Go to UniProtKB:  P0ABA0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0ABA0
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.55 Å
  • R-Value Free: 0.313 
  • R-Value Work: 0.282 
  • R-Value Observed: 0.285 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 35.7α = 90
b = 40.76β = 90
c = 42.35γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-06-05
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2018-01-31
    Changes: Experimental preparation
  • Version 1.4: 2024-02-14
    Changes: Advisory, Data collection, Database references