Structural basis for cofilin binding and actin filament disassembly.

ABSTRACT: Actin depolymerizing factor (ADF) and cofilin accelerate actin dynamics by severing and disassembling actin filaments. Here, we present the 3.8?Å resolution cryo-EM structure of cofilactin (cofilin-decorated actin filament). The actin subunit structure of cofilactin (C-form) is distinct from those of F-actin (F-form) and monomeric actin (G-form). During the transition between these three conformations, the inner domain of actin (subdomains 3 and 4) and the majority of subdomain 1 move as two separate rigid bodies. The cofilin-actin interface consists of three distinct parts. Based on the rigid body movements of actin and the three cofilin-actin interfaces, we propose models for the cooperative binding of cofilin to actin, preferential binding of cofilin to ADP-bound actin filaments and cofilin-mediated severing of actin filaments.

SUBMITTER: Tanaka K 

PROVIDER: S-EPMC5945598 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature