7W72

Structure of a human glycosylphosphatidylinositol (GPI) transamidase

7W72 の概要

• エントリーDOI: 10.2210/pdb7w72/pdb
• EMDBエントリー: 32336
• 分子名称: Phosphatidylinositol glycan anchor biosynthesis class U protein, GPI transamidase component PIG-S, GPI transamidase component PIG-T, ... (9 entities in total)
• 機能のキーワード: glycosylphosphatidylinositol, transamidase, membrane protein
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 282622.07

構造登録者

Zhang, H.,Su, J.,Li, B.,Gao, Y.,Zhang, X.C.,Zhao, Y. (登録日: 2021-12-02, 公開日: 2022-02-16, 最終更新日: 2025-06-25)

主引用文献

Zhang, H.,Su, J.,Li, B.,Gao, Y.,Liu, M.,He, L.,Xu, H.,Dong, Y.,Zhang, X.C.,Zhao, Y.
Structure of human glycosylphosphatidylinositol transamidase.
Nat.Struct.Mol.Biol., 29:203-209, 2022

PubMed Abstract: Glycosylphosphatidylinositol (GPI) molecules are complex glycophospholipids and serve as membrane anchors for tethering many proteins to the cell surface. Attaching GPI to the protein in the endoplasmic reticulum (ER) is catalyzed by the transmembrane GPI transamidase (GPIT) complex, which is essential for maturation of the GPI-anchored proteins. The GPIT complex is known to be composed of five subunits: PIGK, PIGU, PIGT, PIGS and GPAA1. Here, we determined the structure of the human GPIT complex at a resolution of 3.1 Å using single-particle cryo-EM, elucidating its overall assembly. The PIGK subunit functions as the catalytic component, in which we identified a C206-H164-N58 triad that is critical for the transamination reaction. Transmembrane helices constitute a widely opened cleft, which is located underneath PIGK, serving as a GPI substrate-binding site. The ubiquitin E3 ligase RNF121 is visualized at the back of the complex and probably serves as a quality control factor for the GPIT complex.

PubMed: 35165458
DOI: 10.1038/s41594-022-00726-6

実験手法

ELECTRON MICROSCOPY (3.1 Å)