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-Structure paper
タイトル | Structural basis for membrane attack complex inhibition by CD59. |
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ジャーナル・号・ページ | Nat Commun, Vol. 14, Issue 1, Page 890, Year 2023 |
掲載日 | 2023年2月16日 |
著者 | Emma C Couves / Scott Gardner / Tomas B Voisin / Jasmine K Bickel / Phillip J Stansfeld / Edward W Tate / Doryen Bubeck / |
PubMed 要旨 | CD59 is an abundant immuno-regulatory receptor that protects human cells from damage during complement activation. Here we show how the receptor binds complement proteins C8 and C9 at the membrane to ...CD59 is an abundant immuno-regulatory receptor that protects human cells from damage during complement activation. Here we show how the receptor binds complement proteins C8 and C9 at the membrane to prevent insertion and polymerization of membrane attack complex (MAC) pores. We present cryo-electron microscopy structures of two inhibited MAC precursors known as C5b8 and C5b9. We discover that in both complexes, CD59 binds the pore-forming β-hairpins of C8 to form an intermolecular β-sheet that prevents membrane perforation. While bound to C8, CD59 deflects the cascading C9 β-hairpins, rerouting their trajectory into the membrane. Preventing insertion of C9 restricts structural transitions of subsequent monomers and indirectly halts MAC polymerization. We combine our structural data with cellular assays and molecular dynamics simulations to explain how the membrane environment impacts the dual roles of CD59 in controlling pore formation of MAC, and as a target of bacterial virulence factors which hijack CD59 to lyse human cells. |
リンク | Nat Commun / PubMed:36797260 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.9 - 3.4 Å |
構造データ | EMDB-15779, PDB-8b0f: EMDB-15780, PDB-8b0g: EMDB-15781, PDB-8b0h: EMDB-15782: 2C9, C5b9-CD59 cryoEM structure; focus refinement map EMDB-15783: 3C9, C5b9-CD59 cryoEM structure; focus refinement map EMDB-15800: CryoEM reconstruction of C5b8-CD59, density subtracted |
化合物 | ChemComp-CA: ChemComp-NAG: |
由来 |
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キーワード | IMMUNE SYSTEM (免疫系) / Complement / inhibitor (酵素阻害剤) / complex / pore-forming / MEMBRANE PROTEIN (膜タンパク質) / CD59 / MAC |