7NBX

Lateral-open conformation of the lid-locked BAM complex (BamA E435C S665C, BamBDCE) by cryoEM

7NBX の概要

• エントリーDOI: 10.2210/pdb7nbx/pdb
• 関連するPDBエントリー: 7BNQ
• EMDBエントリー: 12232 12262
• 分子名称: Outer membrane protein assembly factor BamA, Outer membrane protein assembly factor BamB, Outer membrane protein assembly factor BamC, ... (5 entities in total)
• 機能のキーワード: outer membrane protein assembly, beta-barrel, gram negative bacteria, protein foldase, membrane protein
• 由来する生物種: Escherichia coli (strain K12); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 210784.18

構造登録者

Haysom, S.F. (登録日: 2021-01-28, 公開日: 2021-06-02, 最終更新日: 2024-11-13)

主引用文献

White, P.,Haysom, S.F.,Iadanza, M.G.,Higgins, A.J.,Machin, J.M.,Whitehouse, J.M.,Horne, J.E.,Schiffrin, B.,Carpenter-Platt, C.,Calabrese, A.N.,Storek, K.M.,Rutherford, S.T.,Brockwell, D.J.,Ranson, N.A.,Radford, S.E.
The role of membrane destabilisation and protein dynamics in BAM catalysed OMP folding.
Nat Commun, 12:4174-4174, 2021

PubMed Abstract: The folding of β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria is catalysed by the β-barrel assembly machinery (BAM). How lateral opening in the β-barrel of the major subunit BamA assists in OMP folding, and the contribution of membrane disruption to BAM catalysis remain unresolved. Here, we use an anti-BamA monoclonal antibody fragment (Fab1) and two disulphide-crosslinked BAM variants (lid-locked (LL), and POTRA-5-locked (P5L)) to dissect these roles. Despite being lethal in vivo, we show that all complexes catalyse folding in vitro, albeit less efficiently than wild-type BAM. CryoEM reveals that while Fab1 and BAM-P5L trap an open-barrel state, BAM-LL contains a mixture of closed and contorted, partially-open structures. Finally, all three complexes globally destabilise the lipid bilayer, while BamA does not, revealing that the BAM lipoproteins are required for this function. Together the results provide insights into the role of BAM structure and lipid dynamics in OMP folding.

PubMed: 34234105
DOI: 10.1038/s41467-021-24432-x

実験手法

ELECTRON MICROSCOPY (4.8 Å)