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Updated: Mar 26, 2026

Measuring In Vitro ATPase Activity for Enzymatic Characterization
Published on: August 23, 2016
Nucleotide-dependent conformational changes of the AAA+ ATPase p97 revisited
Jan M Schuller1, Florian Beck1, Philip Lössl2
1Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, Martinsried, Germany.
Abstract:
The ubiquitous AAA-ATPase p97 segregates ubiquitylated proteins from their molecular environment. Previous studies of the nucleotide-dependent conformational changes of p97 were inconclusive. Here, we determined its structure in the presence of ADP, AMP-PNP, or ATP-γS at 6.1-7.4 Å resolution using single particle cryo-electron microscopy. Both AAA domains, D1 and D2, assemble into essentially six-fold symmetrical rings. The pore of the D1-ring remains essentially closed under all nucleotide conditions, whereas the D2-ring shows an iris-like opening for ADP. The largest conformational changes of p97 are 'swinging motions' of the N-terminal domains, which may enable segregation of ubiquitylated substrates from their environment.
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