4QCD

Neutron crystal structure of phycocyanobilin:ferredoxin oxidoreductase in complex with biliverdin IXalpha at room temperature.

4QCD の概要

• エントリーDOI: 10.2210/pdb4qcd/pdb
• 関連するPDBエントリー: 2D1E
• 分子名称: Phycocyanobilin:ferredoxin oxidoreductase, BILIVERDINE IX ALPHA, trideuteriooxidanium, ... (4 entities in total)
• 機能のキーワード: bilin reductase, biliverdin ixalpha, oxidoreductase
• 由来する生物種: Synechocystis sp.
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28760.84

構造登録者

Unno, M.,Ishikawa-Suto, K.,Ishihara, M.,Hagiwara, Y.,Sugishima, M.,Wada, K.,Fukuyama, K. (登録日: 2014-05-10, 公開日: 2015-04-29, 最終更新日: 2024-03-20)

主引用文献

Unno, M.,Ishikawa-Suto, K.,Kusaka, K.,Tamada, T.,Hagiwara, Y.,Sugishima, M.,Wada, K.,Yamada, T.,Tomoyori, K.,Hosoya, T.,Tanaka, I.,Niimura, N.,Kuroki, R.,Inaka, K.,Ishihara, M.,Fukuyama, K.
Insights into the Proton Transfer Mechanism of a Bilin Reductase PcyA Following Neutron Crystallography.
J. Am. Chem. Soc., 137:5452-5460, 2015

PubMed Abstract: Phycocyanobilin, a light-harvesting and photoreceptor pigment in higher plants, algae, and cyanobacteria, is synthesized from biliverdin IXα (BV) by phycocyanobilin:ferredoxin oxidoreductase (PcyA) via two steps of two-proton-coupled two-electron reduction. We determined the neutron structure of PcyA from cyanobacteria complexed with BV, revealing the exact location of the hydrogen atoms involved in catalysis. Notably, approximately half of the BV bound to PcyA was BVH(+), a state in which all four pyrrole nitrogen atoms were protonated. The protonation states of BV complemented the protonation of adjacent Asp105. The "axial" water molecule that interacts with the neutral pyrrole nitrogen of the A-ring was identified. His88 Nδ was protonated to form a hydrogen bond with the lactam O atom of the BV A-ring. His88 and His74 were linked by hydrogen bonds via H3O(+). These results imply that Asp105, His88, and the axial water molecule contribute to proton transfer during PcyA catalysis.

PubMed: 25872660
DOI: 10.1021/jacs.5b00645

実験手法

NEUTRON DIFFRACTION (1.932 Å)
X-RAY DIFFRACTION (1.551 Å)