RT Journal Article
SR Electronic
T1 Assembly mechanisms of the bacterial cytoskeletal protein FilP
JF Life Science Alliance
JO Life Sci. Alliance
FD Life Science Alliance LLC
SP e201800290
DO 10.26508/lsa.201800290
VO 2
IS 3
A1 Javadi, Ala
A1 Söderholm, Niklas
A1 Olofsson, Annelie
A1 Flärdh, Klas
A1 Sandblad, Linda
YR 2019
UL https://www.life-science-alliance.org/content/2/3/e201800290.abstract
AB 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.