3IMA

Complex structure of tarocystatin and papain

3IMA の概要

• エントリーDOI: 10.2210/pdb3ima/pdb
• 分子名称: Papain, Cysteine proteinase inhibitor, ACETATE ION, ... (4 entities in total)
• 機能のキーワード: cystatin, tarocystatin, cecpi, papain, phytocystatin, allergen, disulfide bond, hydrolase, protease, thiol protease, zymogen, protease inhibitor, thiol protease inhibitor, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Colocasia esculenta (cocoyam,dasheen,eddo,elephant's ear,kalo,malanga); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 67573.22

構造登録者

Chu, M.H.,Liu, K.L.,Yeh, K.W.,Cheng, Y.S. (登録日: 2009-08-10, 公開日: 2010-02-16, 最終更新日: 2023-11-22)

主引用文献

Chu, M.H.,Liu, K.L.,Wu, H.Y.,Yeh, K.W.,Cheng, Y.S.
Crystal structure of tarocystatin-papain complex: implications for the inhibition property of group-2 phytocystatins.
Planta, 234:243-254, 2011

PubMed Abstract: Tarocystatin (CeCPI) from taro (Colocasia esculenta cv. Kaohsiung no. 1), a group-2 phytocystatin, shares a conserved N-terminal cystatin domain (NtD) with other phytocystatins but contains a C-terminal cystatin-like extension (CtE). The structure of the tarocystatin-papain complex and the domain interaction between NtD and CtE in tarocystatin have not been determined. We resolved the crystal structure of the phytocystatin-papain complex at resolution 2.03 Å. Surprisingly, the structure of the NtD-papain complex in a stoichiometry of 1:1 could be built, with no CtE observed. Only two remnant residues of CtE could be built in the structure of the CtE-papain complex. Therefore, CtE is easily digested by papain. To further characterize the interaction between NtD and CtE, three segments of tarocystatin, including the full-length (FL), NtD and CtE, were used to analyze the domain-domain interaction and the inhibition ability. The results from glutaraldehyde cross-linking and yeast two-hybrid assay indicated the existence of an intrinsic flexibility in the region linking NtD and CtE for most tarocystatin molecules. In the inhibition activity assay, the glutathione-S-transferase (GST)-fused FL showed the highest inhibition ability without residual peptidase activity, and GST-NtD and FL showed almost the same inhibition ability, which was higher than with NtD alone. On the basis of the structures, the linker flexibility and inhibition activity of tarocystatins, we propose that the overhangs from the cystatin domain may enhance the inhibition ability of the cystatin domain against papain.

PubMed: 21416241
DOI: 10.1007/s00425-011-1398-8

実験手法

X-RAY DIFFRACTION (2.03 Å)