5VGL

Crystal structure of lachrymatory factor synthase from Allium cepa

5VGL の概要

• エントリーDOI: 10.2210/pdb5vgl/pdb
• 関連するPDBエントリー: 5VGS
• 分子名称: Lachrymatory-factor synthase (2 entities in total)
• 機能のキーワード: lachrymatory factor, onion, sulfenic acid, isomerase
• 由来する生物種: Allium cepa (Onion)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17577.95

構造登録者

Silvaroli, J.A.,Pleshinger, M.J.,Banerjee, S.,Kiser, P.D.,Golczak, M. (登録日: 2017-04-11, 公開日: 2017-07-26, 最終更新日: 2023-10-04)

主引用文献

Silvaroli, J.A.,Pleshinger, M.J.,Banerjee, S.,Kiser, P.D.,Golczak, M.
Enzyme That Makes You Cry-Crystal Structure of Lachrymatory Factor Synthase from Allium cepa.
ACS Chem. Biol., 12:2296-2304, 2017

PubMed Abstract: The biochemical pathway that gives onions their savor is part of the chemical warfare against microbes and animals. This defense mechanism involves formation of a volatile lachrymatory factor (LF) ((Z)-propanethial S-oxide) that causes familiar eye irritation associated with onion chopping. LF is produced in a reaction catalyzed by lachrymatory factor synthase (LFS). The principles by which LFS facilitates conversion of a sulfenic acid substrate into LF have been difficult to experimentally examine owing to the inherent substrate reactivity and lability of LF. To shed light on the mechanism of LF production in the onion, we solved crystal structures of LFS in an apo-form and in complex with a substrate analogue, crotyl alcohol. The enzyme closely resembles the helix-grip fold characteristic for plant representatives of the START (star-related lipid transfer) domain-containing protein superfamily. By comparing the structures of LFS to that of the abscisic acid receptor, PYL10, a representative of the START protein superfamily, we elucidated structural adaptations underlying the catalytic activity of LFS. We also delineated the architecture of the active site, and based on the orientation of the ligand, we propose a mechanism of catalysis that involves sequential proton transfer accompanied by formation of a carbanion intermediate. These findings reconcile chemical and biochemical information regarding thioaldehyde S-oxide formation and close a long-lasting gap in understanding of the mechanism responsible for LF production in the onion.

PubMed: 28708375
DOI: 10.1021/acschembio.7b00336

実験手法

X-RAY DIFFRACTION (1.4 Å)