3AJG

Crystal structure of PcyA V225D-biliverdin IX alpha complex

3AJG の概要

• エントリーDOI: 10.2210/pdb3ajg/pdb
• 関連するPDBエントリー: 3AJH
• 分子名称: Phycocyanobilin:ferredoxin oxidoreductase, BILIVERDINE IX ALPHA (3 entities in total)
• 機能のキーワード: alpha/beta/alpha sandwich, oxidoreductase
• 由来する生物種: Synechocystis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 57509.52

構造登録者

Wada, K.,Hagiwara, Y.,Fukuyama, K. (登録日: 2010-06-05, 公開日: 2011-03-16, 最終更新日: 2023-11-01)

主引用文献

Wada, K.,Hagiwara, Y.,Yutani, Y.,Fukuyama, K.
One residue substitution in PcyA leads to unexpected changes in tetrapyrrole substrate binding.
Biochem.Biophys.Res.Commun., 402:373-377, 2010

PubMed Abstract: Phycocyanobilin:ferredoxin oxidoreductase (PcyA) catalyzes the sequential reduction of the vinyl group of the D-ring and A-ring of biliverdin IXα (BV), using reducing equivalents provided by ferredoxin. This reaction produces phycocyanobilin, a pigment used for light-harvesting and light-sensing in red algae and cyanobacteria. The crystal structure of PcyA-BV reveals that BV is specifically bound in the PcyA active pocket through extensive hydrophobic and hydrophilic interactions. During the course of a mutational study of PcyA, we observed that mutation of the V225 position, apart from the processing sites, conferred an unusual property on PcyA; V225D mutant protein could bind BV and its analog BV13, but these complexes showed a distinct UV-vis absorption spectrum from that of the wild-type PcyA-BV complex. The crystal structures of BV- and BV13-bound forms of V225D protein revealed that gross structural changes occurred near the substrate-binding pocket, and that the BV/BV13 binding manner in the pocket was dramatically altered. Protein folding in V225D-BV/BV13 was more similar to that of substrate-free PcyA than that in PcyA-BV; the "induced-fit" did not occur when BV/BV13 was bound to the V225D protein. The unexpected structural change presented here provides a cautionary note about interpreting functional data derived from a mutated protein in the absence of its exact structure.

PubMed: 20946883
DOI: 10.1016/j.bbrc.2010.10.037

実験手法

X-RAY DIFFRACTION (1.9 Å)