3S70

Crystal structure of active caspase-6 bound with Ac-VEID-CHO solved by As-SAD

3S70 の概要

• エントリーDOI: 10.2210/pdb3s70/pdb
• 関連するBIRD辞書のPRD_ID: PRD_000976
• 分子名称: Caspase-6, aldehyde inhibitor Ac-VEID-CHO, CACODYLATE ION, ... (6 entities in total)
• 機能のキーワード: caspase-6, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Cytoplasm: P55212
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 66257.62

構造登録者

Su, X.-D.,Liu, X.,Wang, X.-J. (登録日: 2011-05-26, 公開日: 2012-04-11, 最終更新日: 2024-10-16)

主引用文献

Liu, X.,Zhang, H.,Wang, X.-J.,Li, L.-F.,Su, X.-D.
Get phases from arsenic anomalous scattering: de novo SAD phasing of two protein structures crystallized in cacodylate buffer
Plos One, 6:e24227-e24227, 2011

PubMed Abstract: The crystal structures of two proteins, a putative pyrazinamidase/nicotinamidase from the dental pathogen Streptococcus mutans (SmPncA) and the human caspase-6 (Casp6), were solved by de novo arsenic single-wavelength anomalous diffraction (As-SAD) phasing method. Arsenic (As), an uncommonly used element in SAD phasing, was covalently introduced into proteins by cacodylic acid, the buffering agent in the crystallization reservoirs. In SmPncA, the only cysteine was bound to dimethylarsinoyl, which is a pentavalent arsenic group (As (V)). This arsenic atom and a protein-bound zinc atom both generated anomalous signals. The predominant contribution, however, was from the As anomalous signals, which were sufficient to phase the SmPncA structure alone. In Casp6, four cysteines were found to bind cacodyl, a trivalent arsenic group (As (III)), in the presence of the reducing agent, dithiothreitol (DTT), and arsenic atoms were the only anomalous scatterers for SAD phasing. Analyses and discussion of these two As-SAD phasing examples and comparison of As with other traditional heavy atoms that generate anomalous signals, together with a few arsenic-based de novo phasing cases reported previously strongly suggest that As is an ideal anomalous scatterer for SAD phasing in protein crystallography.

PubMed: 21912678
DOI: 10.1371/journal.pone.0024227

実験手法

X-RAY DIFFRACTION (1.625 Å)