The structure of the actin filament uncapping complex mediated by twinfilin.

ABSTRACT: Uncapping of actin filaments is essential for driving polymerization and depolymerization dynamics from capping protein-associated filaments; however, the mechanisms of uncapping leading to rapid disassembly are unknown. Here, we elucidated the x-ray crystal structure of the actin/twinfilin/capping protein complex to address the mechanisms of twinfilin uncapping of actin filaments. The twinfilin/capping protein complex binds to two G-actin subunits in an orientation that resembles the actin filament barbed end. This suggests an unanticipated mechanism by which twinfilin disrupts the stable capping of actin filaments by inducing a G-actin conformation in the two terminal actin subunits. Furthermore, twinfilin disorders critical actin-capping protein interactions, which will assist in the di

SUBMITTER: Mwangangi DM 

PROVIDER: S-EPMC7840138 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature