4OKR

Structures of Toxoplasma gondii MIC2

4OKR の概要

• エントリーDOI: 10.2210/pdb4okr/pdb
• 関連するPDBエントリー: 4OKU
• 分子名称: Micronemal protein MIC2, alpha-D-mannopyranose (3 entities in total)
• 機能のキーワード: vwa domain, integrin i domain, tsr domain, adhesin, gliding motility, cell surface, cell adhesion
• 由来する生物種: Toxoplasma gondii
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 60436.53

構造登録者

Song, G.,Springer, T.A. (登録日: 2014-01-22, 公開日: 2014-03-19, 最終更新日: 2024-11-20)

主引用文献

Song, G.,Springer, T.A.
Structures of the Toxoplasma gliding motility adhesin.
Proc.Natl.Acad.Sci.USA, 111:4862-4867, 2014

PubMed Abstract: Micronemal protein 2 (MIC2) is the key adhesin that supports gliding motility and host cell invasion by Toxoplasma gondii. With a von Willebrand factor A (VWA) domain and six thrombospondin repeat domains (TSR1-6) in its ectodomain, MIC2 connects to the parasite actomyosin system through its cytoplasmic tail. MIC2-associated protein (M2AP) binds noncovalently to the MIC2 ectodomain. MIC2 and M2AP are stored in micronemes as proforms. We find that the MIC2-M2AP ectodomain complex is a highly elongated 1:1 monomer with M2AP bound to the TSR6 domain. Crystal structures of N-terminal fragments containing the VWA and TSR1 domains for proMIC2 and MIC2 reveal a closed conformation of the VWA domain and how it associates with the TSR1 domain. A long, proline-rich, disulfide-bonded pigtail loop in TSR1 overlaps the VWA domain. Mannose α-C-linked to Trp-276 in TSR1 has an unusual (1)C4 chair conformation. The MIC2 VWA domain includes a mobile α5-helix and a 22-residue disordered region containing two disulfide bonds in place of an α6-helix. A hydrophobic residue in the prodomain binds to a pocket adjacent to the α7-helix that pistons in opening of the VWA domain to a putative high-affinity state.

PubMed: 24639528
DOI: 10.1073/pnas.1403059111

実験手法

X-RAY DIFFRACTION (2.601 Å)