+検索条件
-Structure paper
タイトル | The first transmembrane region of complement component-9 acts as a brake on its self-assembly. |
---|---|
ジャーナル・号・ページ | Nat Commun, Vol. 9, Issue 1, Page 3266, Year 2018 |
掲載日 | 2018年8月15日 |
著者 | Bradley A Spicer / Ruby H P Law / Tom T Caradoc-Davies / Sue M Ekkel / Charles Bayly-Jones / Siew-Siew Pang / Paul J Conroy / Georg Ramm / Mazdak Radjainia / Hariprasad Venugopal / James C Whisstock / Michelle A Dunstone / |
PubMed 要旨 | Complement component 9 (C9) functions as the pore-forming component of the Membrane Attack Complex (MAC). During MAC assembly, multiple copies of C9 are sequentially recruited to membrane associated ...Complement component 9 (C9) functions as the pore-forming component of the Membrane Attack Complex (MAC). During MAC assembly, multiple copies of C9 are sequentially recruited to membrane associated C5b8 to form a pore. Here we determined the 2.2 Å crystal structure of monomeric murine C9 and the 3.9 Å resolution cryo EM structure of C9 in a polymeric assembly. Comparison with other MAC proteins reveals that the first transmembrane region (TMH1) in monomeric C9 is uniquely positioned and functions to inhibit its self-assembly in the absence of C5b8. We further show that following C9 recruitment to C5b8, a conformational change in TMH1 permits unidirectional and sequential binding of additional C9 monomers to the growing MAC. This mechanism of pore formation contrasts with related proteins, such as perforin and the cholesterol dependent cytolysins, where it is believed that pre-pore assembly occurs prior to the simultaneous release of the transmembrane regions. |
リンク | Nat Commun / PubMed:30111885 / PubMed Central |
手法 | EM (単粒子) / X線回折 |
解像度 | 2.2 - 3.9 Å |
構造データ | EMDB-7773: The X-ray crystal structure of Complement component-9 reveals that the first trans-membrane region acts as a brake on self-assembly PDB-6cxo: |
化合物 | ChemComp-ZN: ChemComp-CA: ChemComp-NAG: ChemComp-MG: ChemComp-BMA: ChemComp-HOH: |
由来 |
|
キーワード | IMMUNE SYSTEM / Immunity / Complex / Complement / MACPF / pore / EM / membrane / transmembrane |