National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM143052
米国
引用
ジャーナル: Nat Commun / 年: 2022 タイトル: Structural basis for lipid and copper regulation of the ABC transporter MsbA. 著者: Jixing Lyu / Chang Liu / Tianqi Zhang / Samantha Schrecke / Nicklaus P Elam / Charles Packianathan / Georg K A Hochberg / David Russell / Minglei Zhao / Arthur Laganowsky / 要旨: A critical step in lipopolysaccharide (LPS) biogenesis involves flipping lipooligosaccharide, an LPS precursor, from the cytoplasmic to the periplasmic leaflet of the inner membrane, an operation ...A critical step in lipopolysaccharide (LPS) biogenesis involves flipping lipooligosaccharide, an LPS precursor, from the cytoplasmic to the periplasmic leaflet of the inner membrane, an operation carried out by the ATP-binding cassette transporter MsbA. Although LPS binding to the inner cavity of MsbA is well established, the selectivity of MsbA-lipid interactions at other site(s) remains poorly understood. Here we use native mass spectrometry (MS) to characterize MsbA-lipid interactions and guide structural studies. We show the transporter co-purifies with copper(II) and metal binding modulates protein-lipid interactions. A 2.15 Å resolution structure of an N-terminal region of MsbA in complex with copper(II) is presented, revealing a structure reminiscent of the GHK peptide, a high-affinity copper(II) chelator. Our results demonstrate conformation-dependent lipid binding affinities, particularly for the LPS-precursor, 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo)-lipid A (KDL). We report a 3.6 Å-resolution structure of MsbA trapped in an open, outward-facing conformation with adenosine 5'-diphosphate and vanadate, revealing a distinct KDL binding site, wherein the lipid forms extensive interactions with the transporter. Additional studies provide evidence that the exterior KDL binding site is conserved and a positive allosteric modulator of ATPase activity, serving as a feedforward activation mechanism to couple transporter activity with LPS biosynthesis.
履歴
登録
2022年7月8日
登録サイト: RCSB / 処理サイト: RCSB
改定 1.0
2022年12月14日
Provider: repository / タイプ: Initial release
改定 1.1
2024年6月12日
Group: Data collection / カテゴリ: chem_comp_atom / chem_comp_bond