3IKU

Structural model of ParM filament in closed state from cryo-EM

3IKU の概要

• エントリーDOI: 10.2210/pdb3iku/pdb
• 関連するPDBエントリー: 3IKY
• EMDBエントリー: 5128 5129
• 分子名称: Plasmid segregation protein parM (1 entity in total)
• 機能のキーワード: actin-like protein, polymorphic filaments, plasmid, plasmid partition, structural protein
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 429652.50

構造登録者

Galkin, V.E.,Orlova, A.,Rivera, C.,Mullins, R.D.,Egelman, E.H. (登録日: 2009-08-06, 公開日: 2009-09-29, 最終更新日: 2024-02-21)

主引用文献

Galkin, V.E.,Orlova, A.,Rivera, C.,Mullins, R.D.,Egelman, E.H.
Structural polymorphism of the ParM filament and dynamic instability
Structure, 17:1253-1264, 2009

PubMed Abstract: Segregation of the R1 plasmid in bacteria relies on ParM, an actin homolog that segregates plasmids by switching between cycles of polymerization and depolymerization. We find similar polymerization kinetics and stability in the presence of either ATP or GTP and a 10-fold affinity preference for ATP over GTP. We used electron cryo-microscopy to evaluate the heterogeneity within ParM filaments. In addition to variable twist, ParM has variable axial rise, and both parameters are coupled. Subunits in the same ParM filaments can exist in two different structural states, with the nucleotide-binding cleft closed or open, and the bound nucleotide biases the distribution of states. The interface between protomers is different between these states, and in neither state is it similar to F-actin. Our results suggest that the closed state of the cleft is required but not sufficient for ParM polymerization, and provide a structural basis for the dynamic instability of ParM filaments.

PubMed: 19748346
DOI: 10.1016/j.str.2009.07.008

実験手法

ELECTRON MICROSCOPY (18 Å)