Bacterial tubulin TubZ-Bt transitions between a two-stranded intermediate and a four-stranded filament upon GTP hydrolysis.

ABSTRACT: Cytoskeletal filaments form diverse superstructures that are highly adapted for specific functions. The recently discovered TubZ subfamily of tubulins is involved in type III plasmid partitioning systems, facilitating faithful segregation of low copy-number plasmids during bacterial cell division. One such protein, TubZ-Bt, is found on the large pBtoxis plasmid in Bacillus thuringiensis, and interacts via its extended C terminus with a DNA adaptor protein TubR. Here, we use cryo-electron microscopy to determine the structure of TubZ-Bt filaments and light scattering to explore their mechanism of polymerization. Surprisingly, we find that the helical filament architecture is remarkably sensitive to nucleotide state, changing from two-stranded to four-stranded depending on the ability of Tub

SUBMITTER: Montabana EA 

PROVIDER: S-EPMC3948286 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature