Three-dimensional structure of the intact Thermus thermophilus H+-ATPase/synthase by electron microscopy.
ATPases are unique rotary motors that are essential to all living organisms because of their role in energy interconversion. A three-dimensional reconstruction of the intact H+-ATPase/synthase from Thermus thermophilus has revealed the presence of two interconnected peripheral stalks, a well-defined central stalk, and a hexagonally shaped hydrophobic domain. The peripheral stalks are each attached to the water soluble sector at a noncatalytic subunit interface and extend down toward the membrane where they interact with a strong elongated tube of density that runs parallel to the membrane and connects the two stalks. The central stalk is well resolved, especially with respect to its interaction with a single catalytic subunit giving rise to an asymmetry comparable to that identified in F-ATPases. The hexagonal shape of the membrane domain might suggest the presence of 12 proteolipids arranged as dimers, analogous to the proposed arrangement in the related eukaryotic V-ATPases.
MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom. rbernal@mrc-lmb.cam.ac.uk
Ricardo A
RA
Bernal
Daniela
D
Stock
D000818:Animals; D002417:Cattle; D018360:Crystallography, X-Ray; D008854:Microscopy, Electron; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D040681:Structural Homology, Protein; D016963:Thermus thermophilus / Q000201:enzymology*; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry*
D025262:Vacuolar Proton-Translocating ATPases