4QUJ

Caspase-3 T140GV266H

4QUJ の概要

• エントリーDOI: 10.2210/pdb4quj/pdb
• 関連するPDBエントリー: 4QTX 4QU0 4QU5 4QU8 4QU9 4QUA 4QUB 4QUD 4QUE 4QUG 4QUH 4QUI 4QUL
• 関連するBIRD辞書のPRD_ID: PRD_000238
• 分子名称: Caspase-3, ACE-ASP-GLU-VAL-ASP-CHLOROMETHYLKETONE INHIBITOR, SODIUM ION, ... (6 entities in total)
• 機能のキーワード: allosteric network, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: P42574
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 32545.19

構造登録者

Cade, C.,Swartz, P.D.,MacKenzie, S.H.,Clark, A.C. (登録日: 2014-07-10, 公開日: 2014-11-05, 最終更新日: 2024-10-30)

主引用文献

Cade, C.,Swartz, P.,MacKenzie, S.H.,Clark, A.C.
Modifying caspase-3 activity by altering allosteric networks.
Biochemistry, 53:7582-7595, 2014

PubMed Abstract: Caspases have several allosteric sites that bind small molecules or peptides. Allosteric regulators are known to affect caspase enzyme activity, in general, by facilitating large conformational changes that convert the active enzyme to a zymogen-like form in which the substrate-binding pocket is disordered. Mutations in presumed allosteric networks also decrease activity, although large structural changes are not observed. Mutation of the central V266 to histidine in the dimer interface of caspase-3 inactivates the enzyme by introducing steric clashes that may ultimately affect positioning of a helix on the protein surface. The helix is thought to connect several residues in the active site to the allosteric dimer interface. In contrast to the effects of small molecule allosteric regulators, the substrate-binding pocket is intact in the mutant, yet the enzyme is inactive. We have examined the putative allosteric network, in particular the role of helix 3, by mutating several residues in the network. We relieved steric clashes in the context of caspase-3(V266H), and we show that activity is restored, particularly when the restorative mutation is close to H266. We also mimicked the V266H mutant by introducing steric clashes elsewhere in the allosteric network, generating several mutants with reduced activity. Overall, the data show that the caspase-3 native ensemble includes the canonical active state as well as an inactive conformation characterized by an intact substrate-binding pocket, but with an altered helix 3. The enzyme activity reflects the relative population of each species in the native ensemble.

PubMed: 25343534
DOI: 10.1021/bi500874k

実験手法

X-RAY DIFFRACTION (1.498 Å)