Figure 1.

Structures of wild-type and mutant p97 N–D1 with bound ADP or ATPγS. Mutations, either identified in IBMPFD patients (yellow) or introduced in this work (R86A in red and R53A in green), are shown as ball-and-stick models. The N-domains are in magenta and the colours of the D1-domains are alternating in grey (cognate of N) and blue. (A) A schematic diagram for the domain arrangement of p97. (B) Mapping of various mutations to the Cα trace of the wild-type p97 hexamer with bound ADP (PDB:1E32) (Zhang et al, 2000). The structure is viewed down the six-fold axis from the D1- to D2-domain. (C) Stereoscopic rendition of a magnified portion in Figure 1B showing a detailed distribution of mutations in p97 with bound ADP. All mutation sites are labelled. (D) Mapping of various mutations to the Cα trace of the mutant (R155H) structure with bound Mg²⁺·ATPγS. (E) A stereo pair showing a detailed distribution of the mutation sites in the ATPγS-bound structure. (F) Superposition of the hexamers of the ATPγS and ADP forms. The two structures are portrayed in Cα traces with the N-domain from the ATPγS form in pink and that from the ADP form in magenta. Diameters and heights for the hexamers are given. (G) A stereo pair showing a portion of the superposition in Figure 1F. The superposition was based solely on the D1 RecA-like domain. The ADP form shows the N-domain in magenta, N–D1 linker in forest green, and D1-domain in dark blue, whereas the ATPγS form has its N-domain coloured in pink, N–D1 linker in light green, and D1-domain in light blue.