2H7W

Crystal structure of Chagasin, the endogenous cysteine-protease inhibitor from Trypanosoma cruzi

2H7W の概要

• エントリーDOI: 10.2210/pdb2h7w/pdb
• 分子名称: Chagasin (2 entities in total)
• 機能のキーワード: beta-strands, immunoglobulin-fold, hydrolase inhibitor
• 由来する生物種: Trypanosoma cruzi
• 細胞内の位置: Flagellar pocket : Q966X9
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 28958.15

構造登録者

Figueiredo da Silva, A.A.,Guimaraes, B.G. (登録日: 2006-06-05, 公開日: 2006-10-10, 最終更新日: 2024-02-14)

主引用文献

Figueiredo da Silva, A.A.,Vieira, L.C.,Krieger, M.A.,Goldenberg, S.,Zanchin, N.I.,Guimaraes, B.G.
Crystal structure of chagasin, the endogenous cysteine-protease inhibitor from Trypanosoma cruzi.
J.Struct.Biol., 157:416-423, 2007

PubMed Abstract: Trypanosoma cruzi chagasin belongs to a recently discovered family of cysteine protease inhibitors found in lower eukaryotes and prokaryotes but not in mammals. Chagasin binds tightly to cruzain, the major lysosomal T. cruzi cysteine protease, involved with infectivity and survival of the parasite in mammalian host cells. In the scope of a project to characterize proteins diferentially expressed during T. cruzi metacyclogenesis, we have determined the crystal structure of chagasin, which is now the first X-ray structure of a chagasin-like cysteine protease inhibitor to be reported. The structure was solved by the SIRAS method and refined at 1.7A resolution and a comparison with the two NMR structures available revealed some differences in the loops involved in binding to cysteine proteases. The highly flexible loop 4 could be entirely modeled and residues 29-33 from loop 2 form a 3(10)-helix structure that may be important to stabilize the loop conformation. Chagasin crystal structure was docked to the highest resolution structure available of cruzain and a model of chagasin-cruzain interaction was analyzed. The knowledge of the chagasin crystal structure may contribute to the elucidation of the molecular mechanism involved in the inhibition of cruzain and other T. cruzi cysteine proteases.

PubMed: 17011790
DOI: 10.1016/j.jsb.2006.07.017

実験手法

X-RAY DIFFRACTION (1.7 Å)