ジャーナル: EMBO J / 年: 2024 タイトル: Structural insights into the activation mechanism of antimicrobial GBP1. 著者: Marius Weismehl / Xiaofeng Chu / Miriam Kutsch / Paul Lauterjung / Christian Herrmann / Misha Kudryashev / Oliver Daumke / 要旨: The dynamin-related human guanylate-binding protein 1 (GBP1) mediates host defenses against microbial pathogens. Upon GTP binding and hydrolysis, auto-inhibited GBP1 monomers dimerize and assemble ...The dynamin-related human guanylate-binding protein 1 (GBP1) mediates host defenses against microbial pathogens. Upon GTP binding and hydrolysis, auto-inhibited GBP1 monomers dimerize and assemble into soluble and membrane-bound oligomers, which are crucial for innate immune responses. How higher-order GBP1 oligomers are built from dimers, and how assembly is coordinated with nucleotide-dependent conformational changes, has remained elusive. Here, we present cryo-electron microscopy-based structural data of soluble and membrane-bound GBP1 oligomers, which show that GBP1 assembles in an outstretched dimeric conformation. We identify a surface-exposed helix in the large GTPase domain that contributes to the oligomerization interface, and we probe its nucleotide- and dimerization-dependent movements that facilitate the formation of an antimicrobial protein coat on a gram-negative bacterial pathogen. Our results reveal a sophisticated activation mechanism for GBP1, in which nucleotide-dependent structural changes coordinate dimerization, oligomerization, and membrane binding to allow encapsulation of pathogens within an antimicrobial protein coat.
ChemComp-GDP: GUANOSINE-5'-DIPHOSPHATE / GDP / GDP, エネルギー貯蔵分子*YM
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実験情報
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構造解析
手法
クライオ電子顕微鏡法
解析
サブトモグラム平均法
試料の集合状態
particle
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試料調製
濃度
0.68 mg/mL
緩衝液
pH: 7.9 詳細: 50 mM Tris-HCl, 150 mM NaCl, 5 mM MgCl2 (supplemented with 200 uM GDP, 300 uM AlCl3, 10 mM NaF)
凍結
凍結剤: ETHANE
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
撮影
フィルム・検出器のモデル: GATAN K3 (6k x 4k) / 平均電子線量: 2.8 e/Å2 詳細: Tilt series were acquired with a Hybrid-STA (Sanchez et al. 2020, Nat Commun): exposure dose of 2.8 e-/A2 for non-zero tilted projection and 14.4 e-/A2 for zero tilted projection