The structure of the V(1)-ATPase determined by three-dimensional electron microscopy of single particles.
We determined the structure of the V(1)-ATPase from Manduca sexta to a resolution of 1.8 nm, which for the first time reveals internal features of the enzyme. The V(1)-ATPase consists of a headpiece of 13.5 nm in diameter, with six elongated subunits, A(3) and B(3), of approximately equal size, and a stalk of 6 nm in length that connects V(1) with the membrane-bound domain, V(O). At the center of the molecule is a cavity that extends throughout the length of the A(3)B(3) hexamer. Inside the cavity the central stalk can be seen connected to only two of the catalytic A subunits. The structure was obtained by a combination of the Random Conical Reconstruction Technique and angular refinements. Additional recently developed techniques that were used include methods for simultaneous translational rotational alignment of the 0 degrees images, contrast transfer function correction for tilt images, and the Two-Step Radon Inversion Algorithm.
Radermacher
M
M
Max-Planck-Institut für Biophysik, Abt. Strukturbiologie, Heinrich Hoffmann Strasse 7, Frankfurt/M., D-60528, Germany. michael.radermacher@mpibp-frankfurt.mpg.de
Ruiz
T
T
Wieczorek
H
H
Grüber
G
G
D000818:Animals; D003432:Cross-Linking Reagents; D016208:Databases, Factual; D004591:Electrophoresis, Polyacrylamide Gel; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018402:Manduca / Q000201:enzymology*; D008433:Mathematics; D008854:Microscopy, Electron; D008961:Models, Structural; D011487:Protein Conformation; D017494:Proton Pumps / Q000648:ultrastructure; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure; D014617:Vacuoles / Q000201:enzymology
D003432:Cross-Linking Reagents; D017494:Proton Pumps; D025262:Vacuolar Proton-Translocating ATPases