3J4T

Helical model of TubZ-Bt two-stranded filament

3J4T の概要

• エントリーDOI: 10.2210/pdb3j4t/pdb
• 関連するPDBエントリー: 2XKA 3J4T
• EMDBエントリー: 5762 5763
• 分子名称: FtsZ/tubulin-related protein (1 entity in total)
• 機能のキーワード: tubz, ftsz-like, tubulin-like, plasmid segregation, structural protein
• 由来する生物種: Bacillus thuringiensis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 55052.44

構造登録者

Agard, D.A.,Montabana, E.A. (登録日: 2013-10-04, 公開日: 2014-02-19, 最終更新日: 2024-02-21)

主引用文献

Montabana, E.A.,Agard, D.A.
Bacterial tubulin TubZ-Bt transitions between a two-stranded intermediate and a four-stranded filament upon GTP hydrolysis.
Proc.Natl.Acad.Sci.USA, 111:3407-3412, 2014

PubMed 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 TubZ-Bt to hydrolyze GTP. We present pseudoatomic models of both the two- and four-protofilament forms based on cryo-electron microscopy reconstructions (10.8 Å and 6.9 Å, respectively) of filaments formed under different nucleotide states. These data lead to a model in which the two-stranded filament is a necessary intermediate along the pathway to formation of the four-stranded filament. Such nucleotide-directed structural polymorphism is to our knowledge an unprecedented mechanism for the formation of polar filaments.

PubMed: 24550513
DOI: 10.1073/pnas.1318339111

実験手法

ELECTRON MICROSCOPY (10.8 Å)