6T25

Cryo-EM structure of phalloidin-Alexa Flour-546-stabilized F-actin (copolymerized)

Summary for 6T25

• Entry DOI: 10.2210/pdb6t25/pdb
• Related: 5OOC 5OOD 6T1Y 6T20 6T23 6T24
• EMDB information: 10363 10364 10365 10366 10367 3836 3837
• Descriptor: Actin, alpha skeletal muscle, phalloidin, ADENOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: cytoskeleton, phalloidin, stabilized-actin filament, structural protein
• Biological source: Oryctolagus cuniculus (Rabbit); More
• Total number of polymer chains: 10
• Total formula weight: 215680.19

Authors

Pospich, S.,Merino, F.,Raunser, S. (deposition date: 2019-10-07, release date: 2020-03-04, Last modification date: 2020-04-15)

Primary citation

Pospich, S.,Merino, F.,Raunser, S.
Structural Effects and Functional Implications of Phalloidin and Jasplakinolide Binding to Actin Filaments.
Structure, 28:437-449.e5, 2020

PubMed Abstract: Actin undergoes structural transitions during polymerization, ATP hydrolysis, and subsequent release of inorganic phosphate. Several actin-binding proteins sense specific states during this transition and can thus target different regions of the actin filament. Here, we show in atomic detail that phalloidin, a mushroom toxin that is routinely used to stabilize and label actin filaments, suspends the structural changes in actin, likely influencing its interaction with actin-binding proteins. Furthermore, high-resolution cryoelectron microscopy structures reveal structural rearrangements in F-actin upon inorganic phosphate release in phalloidin-stabilized filaments. We find that the effect of the sponge toxin jasplakinolide differs from the one of phalloidin, despite their overlapping binding site and similar interactions with the actin filament. Analysis of structural conformations of F-actin suggests that stabilizing agents trap states within the natural conformational space of actin.

PubMed: 32084355
DOI: 10.1016/j.str.2020.01.014

Experimental method

ELECTRON MICROSCOPY (3.6 Å)