9NUE

Y20S after Mg2+ (Sec18) - Class 3

9NUE の概要

• エントリーDOI: 10.2210/pdb9nue/pdb
• EMDBエントリー: 49802
• 分子名称: Vesicular-fusion protein SEC18, MAGNESIUM ION, ADENOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: snare, nsf, sec18, aaa+, translocase
• 由来する生物種: Saccharomyces cerevisiae (brewer's yeast)
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 597246.69

構造登録者

Khan, Y.A.,Brunger, A.T. (登録日: 2025-03-19, 公開日: 2025-10-01)

主引用文献

Khan, Y.A.,White, K.I.,Pfuetzner, R.A.,Singal, B.,Esquivies, L.,Mckenzie, G.,Liu, F.,DeLong, K.,Choi, U.B.,Montabana, E.,Mclaughlin, T.,Wickner, W.T.,Brunger, A.T.
SNARE disassembly requires Sec18/NSF side loading.
Nat.Struct.Mol.Biol., 32:1708-1720, 2025

PubMed Abstract: SNARE (soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor) proteins drive membrane fusion at different cell compartments as their core domains zipper into a parallel four-helix bundle. After fusion, these bundles are disassembled by the AAA+ (ATPase associated with diverse cellular activities) protein Sec18/NSF and its adaptor Sec17/α-SNAP to make them available for subsequent rounds of membrane fusion. SNARE domains are often flanked by C-terminal transmembrane or N-terminal domains. Previous structures of the NSF-α-SNAP-SNARE complex revealed binding to the D1 ATPase pore, posing a topological constraint as SNARE transmembrane domains would prevent complete substrate threading as suggested for other AAA+ systems. Using mass spectrometry in yeast cells, we show N-terminal SNARE domain interactions with Sec18, exacerbating this topological issue. We present cryo-electron microscopy (cryo-EM) structures of a yeast SNARE complex, Sec18 and Sec17 in a nonhydrolyzing condition, which show SNARE Sso1 threaded through the D1 and D2 ATPase rings of Sec18, with its folded, N-terminal Habc domain interacting with the D2 ring. This domain does not unfold during Sec18/NSF activity. Cryo-EM structures under hydrolyzing conditions revealed substrate-released and substrate-free states of Sec18 with a coordinated opening in the side of the ATPase rings. Thus, Sec18/NSF operates by substrate side loading and unloading topologically constrained SNARE substrates.

PubMed: 40604310
DOI: 10.1038/s41594-025-01590-w

実験手法

ELECTRON MICROSCOPY (3.36 Å)