Elucidation of the stator organization in the V-ATPase of Neurospora crassa.
V-ATPases are membrane protein complexes that pump protons in the lumen of various subcellular compartments at the expense of ATP. Proton pumping is done by a rotary mechanism that requires a static connection between the membrane pumping domain (V(0)) and the extrinsic catalytic head (V(1)). This static connection is composed of several known subunits of the V-ATPase, but their location and topological relationships are still a matter of controversy. Here, we propose a model for the V-ATPase of Neurospora crassa on the basis of single-particle analysis by electron microscopy. Comparison of the resulting map to that of the A-ATPase from Thermus thermophilus allows the positioning of two subunits in the static connecting region that are unique to eukaryotic V-ATPases (C and H). These two subunits seem to be located on opposite sides of a semicircular arrangement of the peripheral connecting elements, suggesting a role in stabilizing the stator in V-ATPases.
Venzke
David
D
EMBL-Heidelberg Meyerhofstrasse 1, 69117 Heidelberg, Germany.
Domgall
Ines
I
Köcher
Thomas
T
Féthière
James
J
Fischer
Susanne
S
Böttcher
Bettina
B
D007425:Intracellular Membranes / Q000201:enzymology; D008854:Microscopy, Electron; D008958:Models, Molecular; D009492:Neurospora crassa / Q000201:enzymology*; D017434:Protein Structure, Tertiary; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry* / Q000302:isolation & purification; D014617:Vacuoles / Q000201:enzymology
D025262:Vacuolar Proton-Translocating ATPases