9BC3

Transglutaminase 2 - Alternate state

これはPDB形式変換不可エントリーです。

9BC3 の概要

• エントリーDOI: 10.2210/pdb9bc3/pdb
• 分子名称: Protein-glutamine gamma-glutamyltransferase 2, HB-225 (gluten peptidomimetic TG2 inhibitor), CALCIUM ION, ... (4 entities in total)
• 機能のキーワード: transglutaminase 2, alternate state, transferase
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 156347.39

構造登録者

Mathews, I.I.,Sewa, A.S.,Khosla, C. (登録日: 2024-04-07, 公開日: 2024-07-03, 最終更新日: 2024-07-17)

主引用文献

Sewa, A.S.,Besser, H.A.,Mathews, I.I.,Khosla, C.
Structural and mechanistic analysis of Ca 2+ -dependent regulation of transglutaminase 2 activity using a Ca 2+ -bound intermediate state.
Proc.Natl.Acad.Sci.USA, 121:e2407066121-e2407066121, 2024

PubMed Abstract: Mammalian transglutaminases, a family of Ca-dependent proteins, are implicated in a variety of diseases. For example, celiac disease (CeD) is an autoimmune disorder whose pathogenesis requires transglutaminase 2 (TG2) to deamidate select glutamine residues in diet-derived gluten peptides. Deamidation involves the formation of transient γ-glutamyl thioester intermediates. Recent studies have revealed that in addition to the deamidated gluten peptides themselves, their corresponding thioester intermediates are also pathogenically relevant. A mechanistic understanding of this relevance is hindered by the absence of any structure of Ca-bound TG2. We report the X-ray crystallographic structure of human TG2 bound to an inhibitory gluten peptidomimetic and two Ca ions in sites previously designated as S1 and S3. Together with additional structure-guided experiments, this structure provides a mechanistic explanation for how S1 regulates formation of an inhibitory disulfide bond in TG2, while also establishing that S3 is essential for γ-glutamyl thioester formation. Furthermore, our crystallographic findings and associated analyses have revealed that i) two interacting residues, H305 and E363, play a critical role in resolving the thioester intermediate into an isopeptide bond (transamidation) but not in thioester hydrolysis (deamidation); and ii) residues N333 and K176 stabilize preferred TG2 substrates and inhibitors via hydrogen bonding to nonreactive backbone atoms. Overall, the intermediate-state conformer of TG2 reported here represents a superior model to previously characterized conformers for both transition states of the TG2-catalyzed reaction.

PubMed: 38959038
DOI: 10.1073/pnas.2407066121

実験手法

X-RAY DIFFRACTION (2.52 Å)