Structures of the free and capped ends of the actin filament

• DOI: 10.1126/science.adg6812
• Publication Date: 2023-05-25T17:59:47Z
• Authors: Peter J. Carman; Kyle R. Barrie; Grzegorz Rebowski; Roberto Dominguez
• Keywords: Tropomyosin

The barbed and pointed ends of the actin filament (F-actin) are sites growth shrinkage targets capping proteins that block subunit exchange, including CapZ at end tropomodulin end. We describe cryo-electron microscopy structures free capped F-actin. Terminal subunits adopt a "flat" F-actin conformation. binds with minor changes to but major itself. By contrast, "twisted" monomeric (G-actin) Tropomodulin binding forces second into an reveal how differ from middle in these differences control addition, dissociation, capping, interactions end-binding proteins.