8TR9

Cryo-EM structure of transglutaminase 2 bound to GDP

8TR9 の概要

• エントリーDOI: 10.2210/pdb8tr9/pdb
• EMDBエントリー: 41574
• 分子名称: Protein-glutamine gamma-glutamyltransferase 2, GUANOSINE-5'-DIPHOSPHATE (2 entities in total)
• 機能のキーワード: gdp, complex, signaling, g-protein, cancer, cryo-em, transferase
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 77855.88

構造登録者

Aplin, C.,Cerione, R.A. (登録日: 2023-08-09, 公開日: 2024-07-31, 最終更新日: 2025-02-12)

主引用文献

Aplin, C.,Zielinski, K.A.,Pabit, S.,Ogunribido, D.,Katt, W.P.,Pollack, L.,Cerione, R.A.,Milano, S.K.
Distinct conformational states enable transglutaminase 2 to promote cancer cell survival versus cell death.
Commun Biol, 7:982-982, 2024

PubMed Abstract: Transglutaminase 2 (TG2) is a GTP-binding, protein-crosslinking enzyme that has been investigated as a therapeutic target for Celiac disease, neurological disorders, and aggressive cancers. TG2 has been suggested to adopt two conformational states that regulate its functions: a GTP-bound, closed conformation, and a calcium-bound, crosslinking-active open conformation. TG2 mutants that constitutively adopt an open conformation are cytotoxic to cancer cells. Thus, small molecules that bind and stabilize the open conformation of TG2 could offer a new therapeutic strategy. Here, we investigate TG2, using static and time-resolved small-angle X-ray scattering (SAXS) and single-particle cryoelectron microscopy (cryo-EM), to determine the conformational states responsible for conferring its biological effects. We also describe a newly developed TG2 inhibitor, LM11, that potently kills glioblastoma cells and use SAXS to investigate how LM11 affects the conformational states of TG2. Using SAXS and cryo-EM, we show that guanine nucleotides bind and stabilize a monomeric closed conformation while calcium binds to an open state that can form higher order oligomers. SAXS analysis suggests how a TG2 mutant that constitutively adopts the open state binds nucleotides through an alternative mechanism to wildtype TG2. Furthermore, we use time resolved SAXS to show that LM11 increases the ability of calcium to bind and stabilize an open conformation, which is not reversible by guanine nucleotides and is cytotoxic to cancer cells. Taken together, our findings demonstrate that the conformational dynamics of TG2 are more complex than previously suggested and highlight how conformational stabilization of TG2 by LM11 maintains TG2 in a cytotoxic conformational state.

PubMed: 39134806
DOI: 10.1038/s42003-024-06672-x

実験手法

ELECTRON MICROSCOPY (3.2 Å)