Fig. 2.

Visualization of the p97-Ufd1-Npl4 complex by negative stain EM. (A) Single particles of negatively stained p97-Ufd1-Npl4 complex viewed down the p97 6-fold axis. An appendage is found at the periphery of p97 (arrow). (B Left) Class average of 400 particles band-pass filtered to 25 Å and shown with superimposed isodensity contours. (Right) The additional density has the size and shape of the Ufd1-Npl4 complex (yellow). The Ufd1-Npl4 density emanates from one peripheral point on the p97 top view. (C) Gallery of immunocomplexes using purified IgG directed against the C-terminal zinc finger of Npl4. A single IgG (bracket) is observed bound to the p97-Ufd1-Npl4 complex. (D) Gallery of immunocomplexes obtained using a monoclonal antibody against the N-terminal fragment of Ufd1. Similarly, a single IgG is bound per complex. (E) NiNTA-nanogold labeling of the C-terminal His₆-tag of Ufd1. One single gold bead (arrow) is observed per complex. (Scale bars: 5 nm.)