8XEJ

Cryo-EM structure of human XKR8-basigin complex in lipid nanodisc

8XEJ の概要

• エントリーDOI: 10.2210/pdb8xej/pdb
• EMDBエントリー: 38291
• 分子名称: Isoform 2 of Basigin, XK-related protein 8, Fab heavy chain, ... (5 entities in total)
• 機能のキーワード: scramblase, apoptosis, membrane protein, lipid transport
• 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: 112482.01

構造登録者

Sakuragi, T.S.,Kanai, R.K.,Kikkawa, M.K.,Toyoshima, C.T.,Nagata, S.N. (登録日: 2023-12-12, 公開日: 2024-02-28, 最終更新日: 2024-11-06)

主引用文献

Sakuragi, T.,Kanai, R.,Otani, M.,Kikkawa, M.,Toyoshima, C.,Nagata, S.
The role of the C-terminal tail region as a plug to regulate XKR8 lipid scramblase.
J.Biol.Chem., 300:105755-105755, 2024

PubMed Abstract: XK-related 8 (XKR8), in complex with the transmembrane glycoprotein basigin, functions as a phospholipid scramblase activated by the caspase-mediated cleavage or phosphorylation of its C-terminal tail. It carries a putative phospholipid translocation path of multiple hydrophobic and charged residues in the transmembrane region. It also has a crucial tryptophan at the exoplasmic end of the path that regulates its scrambling activity. We herein investigated the tertiary structure of the human XKR8-basigin complex embedded in lipid nanodiscs at an overall resolution of 3.66 Å. We found that the C-terminal tail engaged in intricate polar and van der Waals interactions with a groove at the cytoplasmic surface of XKR8. These interactions maintained the inactive state of XKR8. Point mutations to disrupt these interactions strongly enhanced the scrambling activity of XKR8, suggesting that the activation of XKR8 is mediated by releasing the C-terminal tail from the cytoplasmic groove. We speculate that the cytoplasmic tail region of XKR8 functions as a plug to prevent the scrambling of phospholipids.

PubMed: 38364890
DOI: 10.1016/j.jbc.2024.105755

実験手法

ELECTRON MICROSCOPY (3.66 Å)