8DN8

CryoEM structure of the A. aeolicus WzmWzt transporter bound to 3-O-methyl-D-mannose

8DN8 の概要

• エントリーDOI: 10.2210/pdb8dn8/pdb
• EMDBエントリー: 27556
• 分子名称: ABC transporter, Transport permease protein, 3-O-methyl-alpha-D-mannopyranose (3 entities in total)
• 機能のキーワード: o antigen abc transporter, 3-o-methyl-d-mannose, translocase
• 由来する生物種: Aquifex aeolicus; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 153012.93

構造登録者

Spellmon, N.,Zimmer, J. (登録日: 2022-07-10, 公開日: 2022-09-21, 最終更新日: 2024-06-12)

主引用文献

Spellmon, N.,Muszynski, A.,Gorniak, I.,Vlach, J.,Hahn, D.,Azadi, P.,Zimmer, J.
Molecular basis for polysaccharide recognition and modulated ATP hydrolysis by the O antigen ABC transporter.
Nat Commun, 13:5226-5226, 2022

PubMed Abstract: O antigens are ubiquitous protective extensions of lipopolysaccharides in the extracellular leaflet of the Gram-negative outer membrane. Following biosynthesis in the cytosol, the lipid-linked polysaccharide is transported to the periplasm by the WzmWzt ABC transporter. Often, O antigen secretion requires the chemical modification of its elongating terminus, which the transporter recognizes via a carbohydrate-binding domain (CBD). Here, using components from A. aeolicus, we identify the O antigen structure with methylated mannose or rhamnose as its cap. Crystal and cryo electron microscopy structures reveal how WzmWzt recognizes this cap between its carbohydrate and nucleotide-binding domains in a nucleotide-free state. ATP binding induces drastic conformational changes of its CBD, terminating interactions with the O antigen. ATPase assays and site directed mutagenesis reveal reduced hydrolytic activity upon O antigen binding, likely to facilitate polymer loading into the ABC transporter. Our results elucidate critical steps in the recognition and translocation of polysaccharides by ABC transporters.

PubMed: 36064941
DOI: 10.1038/s41467-022-32597-2

実験手法

ELECTRON MICROSCOPY (3.7 Å)