Fig. 1: Cryo-EM structures of p97–UBXD1 closed and open states.
a, Domain schematics of UBXD1 and p97 (not to scale) showing reported interactions (solid lines) between conserved domains24,27,28,29 and the UBX–NTD interaction previously reported to not occur for UBXD1 (dashed line)20,27,31. b, AlphaFold model of UBXD1 showing structured regions (H1/H2, VIM, H4, PUB, helical lariat and UBX) colored as in a. c, Steady-state ATPase activity (y axis, normalized to activity at 0 nM UBXD1) of p97 at increasing concentrations of UBXD1 (x axis), resulting in a calculated IC50 of 25 nM. Data are from n = 3 independent experiments, each with three technical replicates. Data are presented as mean values from each independent experiment. d, Representative 2D class averages following the initial classification of the full p97–UBXD1 dataset, showing the p97 hexamer and no additional density for UBXD1. Scale bar, 100 Å. e,f, Final cryo-EM reconstructions of p97–UBXD1closed (e) and p97–UBXD1open (f) states with top-view 2D projections showing UBX–PUB density (*) and open p97 ring (arrow) compared to cartoon depictions of the corresponding complexes (top row); cryo-EM density maps (p97–UBXD1open is a composite map; see Methods), colored to show the p97 hexamer (light and dark blue, with protomers labeled P1–P6) and UBXD1 density for the VIM (brown), UBX (yellow) and lariat (orange) domains (bottom row). The 8 Å separation between protomers P1 and P6 is indicated for p97–UBXD1open. g, Low-pass filtered maps and fitted models of p97–UBXD1closed (left) and p97–UBXD1open (right) exhibiting low-resolution density for the PUB domain (gray).
