2QQH

Structure of C8a-MACPF reveals mechanism of membrane attack in complement immune defense

2QQH の概要

• エントリーDOI: 10.2210/pdb2qqh/pdb
• 分子名称: Complement component C8 alpha chain, SULFATE ION, NICKEL (II) ION, ... (4 entities in total)
• 機能のキーワード: macpf, membrane perforation, cleavage on pair of basic residues, complement alternate pathway, complement pathway, cytolysis, egf-like domain, glycoprotein, immune response, innate immunity, membrane attack complex, polymorphism, secreted, immune system, membrane protein
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Secreted: P07357
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37890.10

構造登録者

Hadders, M.A.,Gros, P. (登録日: 2007-07-26, 公開日: 2007-09-25, 最終更新日: 2024-11-20)

主引用文献

Hadders, M.A.,Beringer, D.X.,Gros, P.
Structure of C8alpha-MACPF reveals mechanism of membrane attack in complement immune defense.
Science, 317:1552-1554, 2007

PubMed Abstract: Membrane attack is important for mammalian immune defense against invading microorganisms and infected host cells. Proteins of the complement membrane attack complex (MAC) and the protein perforin share a common MACPF domain that is responsible for membrane insertion and pore formation. We determined the crystal structure of the MACPF domain of complement component C8alpha at 2.5 angstrom resolution and show that it is structurally homologous to the bacterial, pore-forming, cholesterol-dependent cytolysins. The structure displays two regions that (in the bacterial cytolysins) refold into transmembrane beta hairpins, forming the lining of a barrel pore. Local hydrophobicity explains why C8alpha is the first complement protein to insert into the membrane. The size of the MACPF domain is consistent with known C9 pore sizes. These data imply that these mammalian and bacterial cytolytic proteins share a common mechanism of membrane insertion.

PubMed: 17872444
DOI: 10.1126/science.1147103

実験手法

X-RAY DIFFRACTION (2.5 Å)