Related Experiment Video
Updated: Aug 1, 2026
07:17
Purification of Hsp104, a Protein Disaggregase
Published on: September 30, 2011
A major conformational change in p97 AAA ATPase upon ATP binding
I Rouiller1, V M Butel, M Latterich
1Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037, USA.
Molecular Cell
|February 13, 2001
Summary
AAA ATPases, like p97, are crucial for cell functions. This study reveals p97
Area of Science:
- Cellular Biology
- Biochemistry
- Molecular Biology
Background:
- AAA ATPases are essential protein machines involved in various cellular processes.
- The ATPase p97 is a key member of the AAA ATPase superfamily, implicated in organelle membrane fusion.
- Understanding the mechanism of AAA ATPases is critical for deciphering cellular regulation.
Purpose of the Study:
- To elucidate the conformational changes of the ATPase p97 during its functional cycle.
- To investigate the interaction between p97 and its adaptor protein p47.
- To revise the existing model of AAA ATPase function based on new structural insights.
Main Methods:
- Cryoelectron microscopy (Cryo-EM) was employed to determine high-resolution structures.
- Single-particle analysis was used to resolve different conformational states of p97.
- Biochemical assays were performed to study nucleotide binding and hydrolysis.
Main Results:
- A significant conformational change in p97 was observed upon nucleotide binding, not hydrolysis.
- Six p47 adaptor molecules were found to associate with the periphery of the p97 hexamer.
- Structural data revealed the mechanism of nucleotide-dependent conformational changes in p97.
Conclusions:
- The study provides a revised model for AAA ATPase function, emphasizing nucleotide binding as the trigger for conformational changes.
- This revised model offers insights into how p97 and related AAA ATPases regulate cellular activities through conformational modulation.
- The findings highlight the importance of structural studies in understanding complex molecular machines.
Related Concept Videos
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
01:34ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
01:30ATP Driven Pumps III: V-type Pumps
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
01:19Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
01:17The Proteasome Structure
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...