1YNT

Structure of the monomeric form of T. gondii SAG1 surface antigen bound to a human Fab

1YNT の概要

• エントリーDOI: 10.2210/pdb1ynt/pdb
• 関連するPDBエントリー: 1KZQ
• 分子名称: 4F11E12 Fab variable light chain region, 4F11E12 Fab variable heavy chain region, protein L, ... (5 entities in total)
• 機能のキーワード: toxoplasma gondii, recombinant sag1, conformational epitope, immune system
• 由来する生物種: Finegoldia magna; 詳細
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 154548.07

構造登録者

Graille, M.,Stura, E.A.,Bossus, M.,Muller, B.H.,Letourneur, O.,Battail-Poirot, N.,Sibai, G.,Rolland, D.,Le Du, M.H.,Ducancel, F. (登録日: 2005-01-25, 公開日: 2005-12-27, 最終更新日: 2024-11-13)

主引用文献

Graille, M.,Stura, E.A.,Bossus, M.,Muller, B.H.,Letourneur, O.,Battail-Poirot, N.,Sibai, G.,Gauthier, M.,Rolland, D.,Le Du, M.H.,Ducancel, F.
Crystal structure of the complex between the monomeric form of Toxoplasma gondii surface antigen 1 (SAG1) and a monoclonal antibody that mimics the human immune response
J.Mol.Biol., 354:447-458, 2005

PubMed Abstract: Toxoplasma gondii, the intracellular parasite responsible for toxoplasmosis infects more than one-third of the world population and can be life-threatening for fetuses and immunocompromised patients. The surface protein SAG1 is an important immune target, which provides a strong immune response against the invasive tachyzoite while the other forms of the parasite, devoid of SAG1 at their surface, are multiplying. In addition to this role as a "hot spot" decoy, SAG1 is predicted to act as an adhesin during host-cell attachment through its binding to proteoglycans. To begin to understand the relationships between SAG1 epitopes and the ligand-binding site, we have solved the crystal structure of the monomeric form of T.gondii SAG1 complexed to a Fab derived from a monoclonal antibody raised against tachyzoite particles. This antibody competes strongly with human Toxoplasma-specific sera, suggesting that its epitope is part of an immunodominant region present on the surface of SAG1. The structure reveals that this conformational epitope, located within the SAG1 N-terminal domain, does not overlap with the proposed ligand-binding pocket. This study provides the first structural description of the monomeric form of SAG1, and significant insights into its dual role of adhesin and immune target during parasite infection.

PubMed: 16242717
DOI: 10.1016/j.jmb.2005.09.028

実験手法

X-RAY DIFFRACTION (3.1 Å)