9FXB

Cryo-EM structure of the type 1 pilus assembly platform as part of the FimI-bound chaperone-usher pilus complex (FimDHGFAnIC - body 2)

9FXB の概要

• エントリーDOI: 10.2210/pdb9fxb/pdb
• EMDBエントリー: 50847
• 分子名称: Type-1 fimbrial protein, A chain, Chaperone protein FimC, Fimbrin-like protein FimI, ... (4 entities in total)
• 機能のキーワード: chaperone, usher, pilus, termination, membrane protein
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 149962.69

構造登録者

Bachmann, P.,Afanasyev, P.,Boehringer, D.,Glockshuber, R. (登録日: 2024-07-01, 公開日: 2025-06-04, 最終更新日: 2025-12-17)

主引用文献

Bachmann, P.,Afanasyev, P.,Boehringer, D.,Glockshuber, R.
Structures of the Escherichia coli type 1 pilus during pilus rod assembly and after assembly termination.
Nat Commun, 16:4988-4988, 2025

PubMed Abstract: Uropathogenic Escherichia coli strains use filamentous type 1 pili to adhere to and invade uroepithelial cells. The pilus consists of a flexible tip fibrillum, formed by the adhesin FimH and the subunits FimG and FimF. The pilus rod is a helical assembly of up to 3000 copies of the main subunit FimA, terminated by a single copy of the subunit FimI that anchors the rod to the assembly platform FimD in the outer membrane. Although type 1 pilus assembly can be completely reconstituted in vitro, the precise mechanism of assembly termination on FimD is still unknown. Here, we present cryo-electron microscopy structures of the fully assembled pilus with all its components prior to and after incorporation of FimI, capped with the assembly chaperone FimC. The structures reveal that FimD positions the proximal end of the pilus rod at an angle of ca. 50 degrees relative to the plane of the outer membrane. Specific interactions between FimI and FimC, absent in the equivalent FimA-FimC interface of the non-terminated pilus, stabilize the assembly-terminated state. In addition, we present structures of the transition region between the tip fibrillum and the helical rod, showing how FimF aligns the tip fibrillum along the rod axis.

PubMed: 40442073
DOI: 10.1038/s41467-025-60325-z

実験手法

ELECTRON MICROSCOPY (4.3 Å)