8HGQ

The apo-flavodoxin dimer from Synechococcus elongatus PCC 7942

8HGQ の概要

• エントリーDOI: 10.2210/pdb8hgq/pdb
• 分子名称: Flavodoxin, PHOSPHATE ION (3 entities in total)
• 機能のキーワード: flavodoxin, phosphate binding, redox potential, electron transport, fmn binding
• 由来する生物種: Synechococcus elongatus PCC 7942 = FACHB-805 (Anacystis nidulans R2)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20876.59

構造登録者

Liu, S.W.,Chen, Y.Y.,Gong, Y.,Cao, P. (登録日: 2022-11-15, 公開日: 2022-12-14, 最終更新日: 2023-11-29)

主引用文献

Liu, S.,Chen, Y.,Du, T.,Zhao, W.,Liu, X.,Zhang, H.,Yuan, Q.,Gao, L.,Dong, Y.,Gao, X.,Gong, Y.,Cao, P.
A dimer-monomer transition captured by the crystal structures of cyanobacterial apo flavodoxin.
Biochem.Biophys.Res.Commun., 639:134-141, 2022

PubMed Abstract: In cyanobacteria and algae (but not plants), flavodoxin (Fld) replaces ferredoxin (Fd) under stress conditions to transfer electrons from photosystem I (PSI) to ferredoxin-NADP reductase (FNR) during photosynthesis. Fld constitutes a small electron carrier noncovalently bound to flavin mononucleotide (FMN), and also an ideal model for revealing the protein/flavin-binding mechanism because of its relative simplicity compared to other flavoproteins. Here, we report two crystal structures of apo-Fld from Synechococcus sp. PCC 7942, one dimeric structure of 2.09 Å and one monomeric structure of 1.84 Å resolution. Analytical ultracentrifugation showed that in solution, apo-Fld exists both as monomers and dimers. Our dimer structure contains two ligand-binding pockets separated by a distance of 45 Å, much longer than the previous structures of FMN-bound dimers. These results suggested a potential dimer-monomer transition mechanism of cyanobacterial apo-Fld. We further propose that the dimer represents the "standby" state to stabilize itself, while the monomer constitutes the "ready" state to bind FMN. Furthermore, we generated a new docking model of cyanobacterial Fld-FNR complex based on the recently reported cryo-EM structures, and mapped the special interactions between Fld and FNR in detail.

PubMed: 36493556
DOI: 10.1016/j.bbrc.2022.11.089

実験手法

X-RAY DIFFRACTION (2.09 Å)