2V18

Crystal structure of the T. thermophilus dodecin

2V18 の概要

• エントリーDOI: 10.2210/pdb2v18/pdb
• 関連するPDBエントリー: 2UX9 2V19 2V21
• 分子名称: DODECIN, FLAVIN MONONUCLEOTIDE, COENZYME A, ... (4 entities in total)
• 機能のキーワード: flavoprotein, hypothetical protein, flavin binding protein, dodecins, coenzyme a, flavin dimer, flavoprotein putative storage protein
• 由来する生物種: THERMUS THERMOPHILUS
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 103928.75

構造登録者

Meissner, B.,Essen, L.-O. (登録日: 2007-05-22, 公開日: 2007-09-11, 最終更新日: 2023-12-13)

主引用文献

Meissner, B.,Schleicher, E.,Weber, S.,Essen, L.-O.
The Dodecin from Thermus Thermophilus, a Bifunctional Cofactor Storage Protein.
J.Biol.Chem., 282:33142-, 2007

PubMed Abstract: Dodecins are so far the smallest known flavoproteins (68-71 amino acids) and are most likely involved in prokaryotic flavin storage. The dodecin monomers adopt a simple betaalphabetabeta-fold and assemble to hollow sphere-like dodecameric complexes. Flavin binding by the dodecin from Thermus thermophilus showed a 1:1 stoichiometry and apparent dissociation constants in the submicromolar to nanomolar range as characterized by isothermal titration calorimetry and fluorescence titrations. The x-ray structures of the flavin-prebound and FMN-reconstituted state of the T. thermophilus dodecin revealed binding of FMN dimers in a novel si-si- rather than the re-re- orientation of their isoalloxazine moieties as found before in an archaeal dodecin. Electron paramagnetic resonance studies demonstrated that upon reduction the excess electron is localized only on one flavin, thus making dodecin-bound flavins highly refractory to redox chemistry. Besides FMN dimers, trimers of coenzyme A are additionally bound to this eubacterial dodecin along the 3-fold symmetry face II of the dodecin complex. Therefore, dodecins can act as bifunctional cofactor storage proteins that sequester catalytic cofactors in prokaryotes very efficiently in an aggregated and unreactive state.

PubMed: 17855371
DOI: 10.1074/JBC.M704951200

実験手法

X-RAY DIFFRACTION (2.59 Å)