PDBsum entry 5onv

Structural protein

PDB id: 5onv

Contents

Protein chains

371 a.a.

Ligands

ADP ×5

Metals

_MG ×5

References listed in PDB file

Key reference

• Title: Structural transitions of f-Actin upon ATP hydrolysis at near-Atomic resolution revealed by cryo-Em.
• Authors: F.Merino, S.Pospich, J.Funk, T.Wagner, F.Küllmer, H.D.Arndt, P.Bieling, S.Raunser.
• Ref.: Nat Struct Mol Biol, 2018, 25, 528-537. [DOI no: 10.1038/s41594-018-0074-0]
• PubMed id: 29867215

Abstract

The function of actin is coupled to the nucleotide bound to its active site. ATP hydrolysis is activated during polymerization; a delay between hydrolysis and inorganic phosphate (P_i) release results in a gradient of ATP, ADP-P_i and ADP along actin filaments (F-actin). Actin-binding proteins can recognize F-actin's nucleotide state, using it as a local 'age' tag. The underlying mechanism is complex and poorly understood. Here we report six high-resolution cryo-EM structures of F-actin from rabbit skeletal muscle in different nucleotide states. The structures reveal that actin polymerization repositions the proposed catalytic base, His161, closer to the γ-phosphate. Nucleotide hydrolysis and P_i release modulate the conformational ensemble at the periphery of the filament, thus resulting in open and closed states, which can be sensed by coronin-1B. The drug-like toxin jasplakinolide locks F-actin in an open state. Our results demonstrate in detail how ATP hydrolysis links to F-actin's conformational dynamics and protein interaction.