3U2F: Atp Synthase C10 Ring In Proton-Unlocked Conformation At Ph 8.3

The proton pore of the F(1)F(o) ATP synthase consists of a ring of c subunits, which rotates, driven by downhill proton diffusion across the membrane. An essential carboxylate side chain in each subunit provides a proton-binding site. In all the structures of c-rings reported to date, these sites are in a closed, ion-locked state. Structures are here presented of the c(10) ring from Saccharomyces cerevisiae determined at pH 8.3, 6.1 and 5.5, at resolutions of 2.0 A, 2.5 A and 2.0 A, respectively. The overall structure of this mitochondrial c-ring is similar to known homologs, except that the essential carboxylate, Glu59, adopts an open extended conformation. Molecular dynamics simulations reveal that opening of the essential carboxylate is a consequence of the amphiphilic nature of the crystallization buffer. We propose that this new structure represents the functionally open form of the c subunit, which facilitates proton loading and release.
PDB ID: 3U2FDownload
MMDB ID: 97086
PDB Deposition Date: 2011/10/3
Updated in MMDB: 2012/06
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 3U2F: decameric; determined by author and by software (PISA)
Molecular Components in 3U2F
Label Count Molecule
Proteins (10 molecules)
ATP Synthase Subunit C, Mitochondrial(Gene symbol: OLI1)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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