3ZCI

Crystal structure of Helicobacter pylori T4SS protein CagL in a cubic crystal form with a distorted helical conformation of the RGD-motif

3ZCI の概要

• エントリーDOI: 10.2210/pdb3zci/pdb
• 関連するPDBエントリー: 3ZCJ
• 分子名称: CAG PATHOGENICITY ISLAND PROTEIN (CAG18), SULFATE ION, 1,4-DIETHYLENE DIOXIDE, ... (6 entities in total)
• 機能のキーワード: protein binding, kkqek, ser mutant, adhesion, rgd motif, integrin binding, type iv secretion, t4s, virulence, cag18, hp0539
• 由来する生物種: HELICOBACTER PYLORI
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 25798.86

構造登録者

Barden, S.,Niemann, H.H. (登録日: 2012-11-20, 公開日: 2013-10-09, 最終更新日: 2024-10-16)

主引用文献

Barden, S.,Lange, S.,Tegtmeyer, N.,Conradi, J.,Sewald, N.,Backert, S.,Niemann, H.H.
A Helical Rgd Motif Promoting Cell Adhesion: Crystal Structures of the Helicobacter Pylori Type Iv Secretion System Pilus Protein Cagl
Structure, 21:1931-, 2013

PubMed Abstract: RGD tripeptide motifs frequently mediate ligand binding to integrins. The type IV secretion system (T4SS) protein CagL of the gastric pathogen Helicobacter pylori also contains an RGD motif. CagL decorates the T4SS pilus and may function as an adhesin for host cells. Whether CagL binds integrins via its RGD motif is under debate. Here, we present crystal structures of CagL revealing an elongated four-helix bundle that appears evolutionarily unrelated to the proposed VirB5 orthologs. The RGD motif is surface-exposed but located within a long α helix. This is unprecedented as previously characterized integrin-binding RGD motifs are located within extended or flexible loops. Yet, adhesion of gastric epithelial cells to CagL was strictly RGD-dependent. Comparison of seven crystallographically independent molecules reveals substantial structural flexibility. Intramolecular disulfide bonds engineered to reduce CagL flexibility resulted in more stable protein, but unable to support cell adhesion. CagL may thus partly unfold during receptor binding.

PubMed: 24076404
DOI: 10.1016/J.STR.2013.08.018

実験手法

X-RAY DIFFRACTION (2.201 Å)