5I9T

Caspase 3 V266C

5I9T の概要

• エントリーDOI: 10.2210/pdb5i9t/pdb
• 関連するBIRD辞書のPRD_ID: PRD_000238
• 分子名称: Caspase-3, ACE-ASP-GLU-VAL-ASK, ACETATE ION, ... (4 entities in total)
• 機能のキーワード: allostery, saturation mutagenesis, conformational selection, native ensemble, protein solvation, protein structure, protein dynamics, 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: P42574
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 64667.15

構造登録者

Maciag, J.J.,Mackenzie, S.H.,Tucker, M.B.,Schipper, J.L.,Swartz, P.D.,Clark, A.C. (登録日: 2016-02-20, 公開日: 2016-10-26, 最終更新日: 2024-10-23)

主引用文献

Maciag, J.J.,Mackenzie, S.H.,Tucker, M.B.,Schipper, J.L.,Swartz, P.,Clark, A.C.
Tunable allosteric library of caspase-3 identifies coupling between conserved water molecules and conformational selection.
Proc.Natl.Acad.Sci.USA, 113:E6080-E6088, 2016

PubMed Abstract: The native ensemble of caspases is described globally by a complex energy landscape where the binding of substrate selects for the active conformation, whereas targeting an allosteric site in the dimer interface selects an inactive conformation that contains disordered active-site loops. Mutations and posttranslational modifications stabilize high-energy inactive conformations, with mostly formed, but distorted, active sites. To examine the interconversion of active and inactive states in the ensemble, we used detection of related solvent positions to analyze 4,995 waters in 15 high-resolution (<2.0 Å) structures of wild-type caspase-3, resulting in 450 clusters with the most highly conserved set containing 145 water molecules. The data show that regions of the protein that contact the conserved waters also correspond to sites of posttranslational modifications, suggesting that the conserved waters are an integral part of allosteric mechanisms. To test this hypothesis, we created a library of 19 caspase-3 variants through saturation mutagenesis in a single position of the allosteric site of the dimer interface, and we show that the enzyme activity varies by more than four orders of magnitude. Altogether, our database consists of 37 high-resolution structures of caspase-3 variants, and we demonstrate that the decrease in activity correlates with a loss of conserved water molecules. The data show that the activity of caspase-3 can be fine-tuned through globally desolvating the active conformation within the native ensemble, providing a mechanism for cells to repartition the ensemble and thus fine-tune activity through conformational selection.

PubMed: 27681633
DOI: 10.1073/pnas.1603549113

実験手法

X-RAY DIFFRACTION (1.95 Å)