3G37

Cryo-EM structure of actin filament in the presence of phosphate

Summary for 3G37

• Entry DOI: 10.2210/pdb3g37/pdb
• EMDB information: 1674
• Descriptor: Actin, alpha skeletal muscle, ADENOSINE-5'-DIPHOSPHATE, PHOSPHATE ION, ... (4 entities in total)
• Functional Keywords: actin, cytoskeleton, cell adhesion, cellular signaling, cytokinesis, muscle, cryo-em, atp-binding, methylation, muscle protein, nucleotide-binding, phosphoprotein, contractile protein
• Biological source: Oryctolagus cuniculus (rabbit)
• Total number of polymer chains: 12
• Total formula weight: 513115.34

Authors

Wakabayshi, T.,Murakami, K.,Yasunaga, T.,Noguchi, T.Q.,Uyeda, T.Q. (deposition date: 2009-02-02, release date: 2010-11-03, Last modification date: 2025-04-09)

Primary citation

Murakami, K.,Yasunaga, T.,Noguchi, T.Q.,Gomibuchi, Y.,Ngo, K.X.,Uyeda, T.Q.,Wakabayashi, T.
Structural basis for actin assembly, activation of ATP hydrolysis, and delayed phosphate release
Cell(Cambridge,Mass.), 143:275-287, 2010

PubMed Abstract: Assembled actin filaments support cellular signaling, intracellular trafficking, and cytokinesis. ATP hydrolysis triggered by actin assembly provides the structural cues for filament turnover in vivo. Here, we present the cryo-electron microscopic (cryo-EM) structure of filamentous actin (F-actin) in the presence of phosphate, with the visualization of some α-helical backbones and large side chains. A complete atomic model based on the EM map identified intermolecular interactions mediated by bound magnesium and phosphate ions. Comparison of the F-actin model with G-actin monomer crystal structures reveals a critical role for bending of the conserved proline-rich loop in triggering phosphate release following ATP hydrolysis. Crystal structures of G-actin show that mutations in this loop trap the catalytic site in two intermediate states of the ATPase cycle. The combined structural information allows us to propose a detailed molecular mechanism for the biochemical events, including actin polymerization and ATPase activation, critical for actin filament dynamics.

PubMed: 20946985
DOI: 10.1016/j.cell.2010.09.034

Experimental method

ELECTRON MICROSCOPY (6 Å)