FIGURE 1.

Three-dimensional structural model of the yeast vacuolar ATPase. The model was calculated from a data set of 25,000 single images at ∼25 Å resolution. The short arrows and arrowheads point to the elongated- and knob-like densities at the top of the V₁. The long arrows point to the peripheral stalks resolved in the three-dimensional model. The > sign points to a thin connection between subunit C and the membrane domain (see below for a discussion on the binding position of subunit C). The asterisk indicates the location of the N-terminal domain of subunit a (a_nt). The short arrows and arrowheads in B1 point to the alternating A and B subunits in the V₁, respectively. The image in B2 shows the arc-like arrangement of the peripheral stalk proteins surrounding the central stalk. The image in B3 shows the bottom view of the V₀. The asymmetry of the V₀ is indicated by the red circle. For details, see text.