8TSL

S. thermodepolymerans KpsM-KpsE in Apo 2 state with rigid body fitted KpsT

8TSL の概要

• エントリーDOI: 10.2210/pdb8tsl/pdb
• EMDBエントリー: 41595
• 分子名称: Transport permease protein, Capsular biosynthesis protein, ABC transporter ATP-binding protein (3 entities in total)
• 機能のキーワード: abc transporter, capsular polysaccharide, membrane protein
• 由来する生物種: Caldimonas thermodepolymerans; 詳細
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 466509.50

構造登録者

Kuklewicz, J.,Zimmer, J. (登録日: 2023-08-11, 公開日: 2024-04-17, 最終更新日: 2025-05-14)

主引用文献

Kuklewicz, J.,Zimmer, J.
Molecular insights into capsular polysaccharide secretion.
Nature, 628:901-909, 2024

PubMed Abstract: Capsular polysaccharides (CPSs) fortify the cell boundaries of many commensal and pathogenic bacteria. Through the ABC-transporter-dependent biosynthesis pathway, CPSs are synthesized intracellularly on a lipid anchor and secreted across the cell envelope by the KpsMT ABC transporter associated with the KpsE and KpsD subunits. Here we use structural and functional studies to uncover crucial steps of CPS secretion in Gram-negative bacteria. We show that KpsMT has broad substrate specificity and is sufficient for the translocation of CPSs across the inner bacterial membrane, and we determine the cell surface organization and localization of CPSs using super-resolution fluorescence microscopy. Cryo-electron microscopy analyses of the KpsMT-KpsE complex in six different states reveal a KpsE-encaged ABC transporter, rigid-body conformational rearrangements of KpsMT during ATP hydrolysis and recognition of a glycolipid inside a membrane-exposed electropositive canyon. In vivo CPS secretion assays underscore the functional importance of canyon-lining basic residues. Combined, our analyses suggest a molecular model of CPS secretion by ABC transporters.

PubMed: 38570679
DOI: 10.1038/s41586-024-07248-9

実験手法

ELECTRON MICROSCOPY (3.4 Å)