The Structure of the V1-ATPase Determined by Three-Dimensional Electron Microscopy of Single Particles

• DOI: 10.1006/jsbi.2001.4395
• Publication Date: 2002-09-18T18:57:36Z
• Authors: Michael Radermacher; Teresa Ruiz; Helmut Wieczorek; Gerhard Grüber
• Keywords: Random hexamer; Contrast transfer function

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.