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Assembly mechanisms of the bacterial cytoskeletal protein FilP.

ABSTRACT: Despite low-sequence homology, the intermediate filament (IF)-like protein FilP from Streptomyces coelicolor displays structural and biochemical similarities to the metazoan nuclear IF lamin. FilP, like IF proteins, is composed of central coiled-coil domains interrupted by short linkers and flanked by head and tail domains. FilP polymerizes into repetitive filament bundles with paracrystalline properties. However, the cations Na+ and K+ are found to induce the formation of a FilP hexagonal meshwork with the same 60-nm repetitive unit as the filaments. Studies of polymerization kinetics, in combination with EM techniques, enabled visualization of the basic building block-a transiently soluble rod-shaped FilP molecule-and its assembly into protofilaments and filament bundles. Cryoelectron tomography provided a 3D view of the FilP bundle structure and an original assembly model of an IF-like protein of prokaryotic origin, thereby enabling a comparison with the assembly of metazoan IF.

SUBMITTER: Javadi A

PROVIDER: S-EPMC6599971 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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Assembly mechanisms of the bacterial cytoskeletal protein FilP.

Javadi Ala A Söderholm Niklas N Olofsson Annelie A Flärdh Klas K Sandblad Linda L

Life science alliance 20190626 3

Despite low-sequence homology, the intermediate filament (IF)-like protein FilP from Streptomyces coelicolor displays structural and biochemical similarities to the metazoan nuclear IF lamin. FilP, like IF proteins, is composed of central coiled-coil domains interrupted by short linkers and flanked by head and tail domains. FilP polymerizes into repetitive filament bundles with paracrystalline properties. However, the cations Na+ and K+ are found to induce the format ...[more]

PMID: 31243049

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