3A5L

Crystal Structure of a Dictyostelium P109A Mg2+-Actin in Complex with Human Gelsolin Segment 1

Summary for 3A5L

• Entry DOI: 10.2210/pdb3a5l/pdb
• Related: 1C0F 3A5M 3A5N 3A5O
• Descriptor: Gelsolin, Major actin, CALCIUM ION, ... (6 entities in total)
• Functional Keywords: actin, adp, hydrolysis, actin capping, actin-binding, cytoskeleton, atp-binding, nucleotide-binding, structural protein, contractile protein
• Biological source: Homo sapiens (human); More
• Cellular location: Isoform 2: Cytoplasm, cytoskeleton. Isoform 1: Secreted: P06396; Cytoplasm, cytoskeleton: P07830
• Total number of polymer chains: 2
• Total formula weight: 56168.87

Authors

Murakami, K.,Yasunaga, T.,Noguchi, T.Q.,Uyeda, T.Q.,Wakabayashi, T. (deposition date: 2009-08-09, release date: 2010-10-27, Last modification date: 2023-11-01)

Primary citation

Murakami, K.,Yasunaga, T.,Noguchi, T.Q.P.,Gomibuchi, Y.,Ngo, K.X.,Uyeda, T.Q.P.,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

X-RAY DIFFRACTION (2.4 Å)