6U96

Actin phalloidin at BeFx state

Summary for 6U96

• Entry DOI: 10.2210/pdb6u96/pdb
• EMDB information: 20694
• Descriptor: Actin, alpha skeletal muscle, PHALLOIDIN Derivative, ADENOSINE-5'-DIPHOSPHATE (3 entities in total)
• Functional Keywords: actin, phalloidin, beryllium fluoride, structural protein
• Biological source: Oryctolagus cuniculus (Rabbit); More
• Total number of polymer chains: 10
• Total formula weight: 216730.36

Authors

Das, S.,Ge, P.,Durer, Z.A.O.,Grintsevich, E.E.,Zhou, Z.H.,Reisler, E. (deposition date: 2019-09-06, release date: 2020-05-13, Last modification date: 2020-05-20)

Primary citation

Das, S.,Ge, P.,Oztug Durer, Z.A.,Grintsevich, E.E.,Zhou, Z.H.,Reisler, E.
D-loop Dynamics and Near-Atomic-Resolution Cryo-EM Structure of Phalloidin-Bound F-Actin.
Structure, 28:586-, 2020

PubMed Abstract: Detailed molecular information on G-actin assembly into filaments (F-actin), and their structure, dynamics, and interactions, is essential for understanding their cellular functions. Previous studies indicate that a flexible DNase I binding loop (D-loop, residues 40-50) plays a major role in actin's conformational dynamics. Phalloidin, a "gold standard" for actin filament staining, stabilizes them and affects the D-loop. Using disulfide crosslinking in yeast actin D-loop mutant Q41C/V45C, light-scattering measurements, and cryoelectron microscopy reconstructions, we probed the constraints of D-loop dynamics and its contribution to F-actin formation/stability. Our data support a model of residues 41-45 distances that facilitate G- to F-actin transition. We report also a 3.3-Å resolution structure of phalloidin-bound F-actin in the ADP-Pi-like (ADP-BeFx) state. This shows the phalloidin-binding site on F-actin and how the relative movement between its two protofilaments is restricted by it. Together, our results provide molecular details of F-actin structure and D-loop dynamics.

PubMed: 32348747
DOI: 10.1016/j.str.2020.04.004

Experimental method

ELECTRON MICROSCOPY (3.8 Å)