Active conformation of the p97-p47 unfoldase complex

• Published in: Nature communications Vol. 13; no. 1; p. 2640
• Main Authors: Xu, Yang, Han, Han, Cooney, Ian, Guo, Yuxuan, Moran, Noah G., Zuniga, Nathan R., Price, John C., Hill, Christopher P., Shen, Peter S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.05.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 101/28; 631/45/173; 631/45/535/1258/1259; 631/45/612/1254; 631/535/1258/1259; 82/58; Adapters; BASIC BIOLOGICAL SCIENCES; Binding sites; Biochemistry; Cell cycle; Cryoelectron microscopy; Enzyme mechanisms; Homeostasis; Humanities and Social Sciences; Humans; Macromolecules; Models, Molecular; Molecular Chaperones - metabolism; multidisciplinary; Mutation; Polypeptides; Protein Conformation; Proteins; Proteomics; Science; Science (multidisciplinary); Substrates; Ubiquitin; Ubiquitin - metabolism; Ubiquitylated proteins; Valosin Containing Protein - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-30318-3

The p97 AAA+ATPase is an essential and abundant regulator of protein homeostasis that plays a central role in unfolding ubiquitylated substrates. Here we report two cryo-EM structures of human p97 in complex with its p47 adaptor. One of the conformations is six-fold symmetric, corresponds to previously reported structures of p97, and lacks bound substrate. The other structure adopts a helical conformation, displays substrate running in an extended conformation through the pore of the p97 hexamer, and resembles structures reported for other AAA unfoldases. These findings support the model that p97 utilizes a “hand-over-hand” mechanism in which two residues of the substrate are translocated for hydrolysis of two ATPs, one in each of the two p97 AAA ATPase rings. Proteomics analysis supports the model that one p97 complex can bind multiple substrate adaptors or binding partners, and can process substrates with multiple types of ubiquitin modification. The p97 unfoldase is an essential and abundant enzyme that segregates its substrates from macromolecular complexes and organelle membranes. Here, authors determined the structure of human p97 in the act of unfolding an authentic substrate.