5I1M: Yeast V-atpase Average Of Densities, A Subunit Segment

Rotary ATPases couple ATP synthesis or hydrolysis to proton translocation across a membrane. However, understanding proton translocation has been hampered by a lack of structural information for the membrane-embedded a subunit. The V/A-ATPase from the eubacteriumThermus thermophilusis similar in structure to the eukaryotic V-ATPase but has a simpler subunit composition and functions in vivo to synthesize ATP rather than pump protons. We determined theT. thermophilusV/A-ATPase structure by cryo-EM at 6.4 A resolution. Evolutionary covariance analysis allowed tracing of the a subunit sequence within the map, providing a complete model of the rotary ATPase. Comparing the membrane-embedded regions of theT. thermophilusV/A-ATPase and eukaryotic V-ATPase fromSaccharomyces cerevisiaeallowed identification of the alpha-helices that belong to the a subunit and revealed the existence of previously unknown subunits in the eukaryotic enzyme. Subsequent evolutionary covariance analysis enabled construction of a model of the a subunit in theS. cerevisaeV-ATPase that explains numerous biochemical studies of that enzyme. Comparing the two a subunit structures determined here with a structure of the distantly related a subunit from the bovine F-type ATP synthase revealed a conserved pattern of residues, suggesting a common mechanism for proton transport in all rotary ATPases.
PDB ID: 5I1MDownload
MMDB ID: 137353
PDB Deposition Date: 2016/2/5
Updated in MMDB: 2016/04
Experimental Method:
electron microscopy
Resolution: 7  Å
Source Organism:
Similar Structures:
Biological Unit for 5I1M: monomeric; determined by author
Molecular Components in 5I1M
Label Count Molecule
Protein (1 molecule)
V-type Proton Atpase Subunit A, Vacuolar Isoform(Gene symbol: VPH1)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB