2X9O

STRUCTURE OF 15, 16- DIHYDROBILIVERDIN:FERREDOXIN OXIDOREDUCTASE (PebA)

2X9O の概要

• エントリーDOI: 10.2210/pdb2x9o/pdb
• 分子名称: 15,16-DIHYDROBILIVERDIN-FERREDOXIN OXIDOREDUCTASE, BILIVERDINE IX ALPHA (3 entities in total)
• 機能のキーワード: phycobilin synthesis, cyanobacteria, oxidoreductase, phycoerythrobilin
• 由来する生物種: SYNECHOCOCCUS SP.
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28719.73

構造登録者

Busch, A.W.U.,Frankenberg-Dinkel, N.,Hofmann, E. (登録日: 2010-03-23, 公開日: 2011-03-30, 最終更新日: 2024-11-13)

主引用文献

Busch, A.W.U.,Reijerse, E.J.,Lubitz, W.,Frankenberg-Dinkel, N.,Hofmann, E.
Structural and Mechanistic Insight Into the Ferredoxin-Mediated Two-Electron Reduction of Bilins.
Biochem.J., 439:257-, 2011

PubMed Abstract: PEB (phycoerythrobilin) is one of the major open-chain tetrapyrrole molecules found in cyanobacterial light-harvesting phycobiliproteins. In these organisms, two enzymes of the ferredoxin-dependent bilin reductase family work in tandem to reduce BV (biliverdin IXα) to PEB. In contrast, a single cyanophage-encoded enzyme of the same family has been identified to catalyse the identical reaction. Using UV-visible and EPR spectroscopy we investigated the two individual cyanobacterial enzymes PebA [15,16-DHBV (dihydrobiliverdin):ferredoxin oxidoreductase] and PebB (PEB:ferredoxin oxidoreductase) showing that the two subsequent reactions catalysed by the phage enzyme PebS (PEB synthase) are clearly dissected in the cyanobacterial versions. Although a highly conserved aspartate residue is critical for both reductions, a second conserved aspartate residue is only involved in the A-ring reduction of the tetrapyrrole in PebB and PebS. The crystal structure of PebA from Synechococcus sp. WH8020 in complex with its substrate BV at a 1.55 Å (1 Å=0.1 nm) resolution revealed further insight into the understanding of enzyme evolution and function. Based on the structure it becomes obvious that in addition to the importance of certain catalytic residues, the shape of the active site and consequently the binding of the substrate highly determines the catalytic properties.

PubMed: 21729003
DOI: 10.1042/BJ20110814

実験手法

X-RAY DIFFRACTION (1.55 Å)