8VQH

CryoEM structure of BchN-BchB electron acceptor component protein of DPOR

8VQH の概要

• エントリーDOI: 10.2210/pdb8vqh/pdb
• EMDBエントリー: 43443
• 分子名称: Light-independent protochlorophyllide reductase subunit N, Light-independent protochlorophyllide reductase subunit B, IRON/SULFUR CLUSTER, ... (5 entities in total)
• 機能のキーワード: plant protein, electron transfer enzymes, photosynthesis, oxidoreductase
• 由来する生物種: Cereibacter sphaeroides; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 232105.76

構造登録者

Kashyap, R.,Antony, E. (登録日: 2024-01-18, 公開日: 2025-04-30, 最終更新日: 2025-05-07)

主引用文献

Kashyap, R.,Walsh, N.,Deveryshetty, J.,Tokmina-Lukaszewska, M.,Zhao, K.,Gan, Y.J.,Hoffman, B.M.,Sarangi, R.,Bothner, B.,Bennett, B.,Antony, E.
Cryo-EM captures the coordination of asymmetric electron transfer through a di-copper site in DPOR.
Nat Commun, 16:3866-3866, 2025

PubMed Abstract: Enzymes that catalyze long-range electron transfer (ET) reactions often function as higher order complexes that possess two structurally symmetrical halves. The functional advantages for such an architecture remain a mystery. Using cryoelectron microscopy we capture snapshots of the nitrogenase-like dark-operative protochlorophyllide oxidoreductase (DPOR) during substrate binding and turnover. DPOR catalyzes reduction of the C17 = C18 double bond in protochlorophyllide during the dark chlorophyll biosynthetic pathway. DPOR is composed of electron donor (L-protein) and acceptor (NB-protein) component proteins that transiently form a complex in the presence of ATP to facilitate ET. NB-protein is an αβ heterotetramer with two structurally identical halves. However, our structures reveal that NB-protein becomes functionally asymmetric upon substrate binding. Asymmetry results in allosteric inhibition of L-protein engagement and ET in one half. Residues that form a conduit for ET are aligned in one half while misaligned in the other. An ATP hydrolysis-coupled conformational switch is triggered once ET is accomplished in one half. These structural changes are then relayed to the other half through a di-nuclear copper center at the tetrameric interface of the NB-protein and leads to activation of ET and substrate reduction. These findings provide a mechanistic blueprint for regulation of long-range electron transfer reactions.

PubMed: 40274796
DOI: 10.1038/s41467-025-59158-7

実験手法

ELECTRON MICROSCOPY (2.7 Å)