Nucleotide dependent motion and mechanism of action of p97/VCP.

摘要: The AAA (ATPases associated with a variety of cellular activities) family proteins bind, hydrolyze, and release ATP to effect conformational changes, assembly, or disassembly upon their binding partners substrate molecules. One the members this family, hexameric p97/valosin-containing protein p97/VCP, is essential for dislocation misfolded membrane from endoplasmic reticulum. Here, we observe large motions dynamic changes p97/VCP as it proceeds through hydrolysis cycle. analysis based on crystal structures four representative states: APO, AMP-PNP, transition state ADP·AlF3, ADP bound. Two presented herein, AMP-PNP bound, are new structures, ADP·AlF3 structure was re-refined higher resolution. largest occur at two stages during cycle: after, but not upon, nucleotide then following release. primarily in D2 domain, D1 α-helical N-terminal relative relatively stationary invariant D1α/β domain. In addition motions, observed rigid flexible loss γ-phosphate group, further increase flexibility within domains each protomer deviate strict 6-fold symmetry, more exhibiting greater asymmetry compared state, suggesting mechanism action which move about hexamer processive fashion.