8RV2

Structure of the formin INF2 bound to the barbed end of F-actin.

Summary for 8RV2

• Entry DOI: 10.2210/pdb8rv2/pdb
• Related: 8RTT 8RTY 8RU0 8RU2
• EMDB information: 19496 19497 19499 19501 19503 19522
• Descriptor: Actin, alpha skeletal muscle, Isoform 2 of Inverted formin-2, ADENOSINE-5'-DIPHOSPHATE, ... (6 entities in total)
• Functional Keywords: actin, formin, inf2, actin end, barbed end, structural protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 6
• Total formula weight: 338390.93

Authors

Oosterheert, W.,Boiero Sanders, M.,Funk, J.,Prumbaum, D.,Raunser, S.,Bieling, P. (deposition date: 2024-01-31, release date: 2024-04-10, Last modification date: 2024-04-24)

Primary citation

Oosterheert, W.,Boiero Sanders, M.,Funk, J.,Prumbaum, D.,Raunser, S.,Bieling, P.
Molecular mechanism of actin filament elongation by formins.
Science, 384:eadn9560-eadn9560, 2024

PubMed Abstract: Formins control the assembly of actin filaments (F-actin) that drive cell morphogenesis and motility in eukaryotes. However, their molecular interaction with F-actin and their mechanism of action remain unclear. In this work, we present high-resolution cryo-electron microscopy structures of F-actin barbed ends bound by three distinct formins, revealing a common asymmetric formin conformation imposed by the filament. Formation of new intersubunit contacts during actin polymerization sterically displaces formin and triggers its translocation. This "undock-and-lock" mechanism explains how actin-filament growth is coordinated with formin movement. Filament elongation speeds are controlled by the positioning and stability of actin-formin interfaces, which distinguish fast and slow formins. Furthermore, we provide a structure of the actin-formin-profilin ring complex, which resolves how profilin is rapidly released from the barbed end during filament elongation.

PubMed: 38603491
DOI: 10.1126/science.adn9560

Experimental method

ELECTRON MICROSCOPY (3.41 Å)