7ZQQ

Molybdenum storage protein - LB131H

7ZQQ の概要

• エントリーDOI: 10.2210/pdb7zqq/pdb
• 分子名称: Molybdenum storage protein subunit alpha, Molybdenum storage protein subunit beta, ADENOSINE-5'-TRIPHOSPHATE, ... (8 entities in total)
• 機能のキーワード: polyoxotungstate, metal storage, keggin ion, metal binding protein
• 由来する生物種: Azotobacter vinelandii; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 60823.59

構造登録者

Ermler, U.,Aziz, I. (登録日: 2022-05-02, 公開日: 2022-07-27, 最終更新日: 2024-01-31)

主引用文献

Aziz, I.,Kaltwasser, S.,Kayastha, K.,Khera, R.,Vonck, J.,Ermler, U.
The molybdenum storage protein forms and deposits distinct polynuclear tungsten oxygen aggregates.
J.Inorg.Biochem., 234:111904-111904, 2022

PubMed Abstract: Some N-fixing bacteria store Mo to maintain the formation of the vital FeMo-cofactor dependent nitrogenase under Mo depleting conditions. The Mo storage protein (MoSto), developed for this purpose, has the unique capability to compactly deposit molybdate as polyoxometalate (POM) clusters in a (αβ) hexameric cage; the same occurs with the physicochemically related tungstate. To explore the structural diversity of W-based POM clusters, MoSto loaded under different conditions with tungstate and two site-specifically modified MoSto variants were structurally characterized by X-ray crystallography or single-particle cryo-EM. The MoSto cage contains five major locations for POM clusters occupied among others by heptanuclear, Keggin ion and even Dawson-like species also found in bulk solvent under defined conditions. We found both lacunary derivatives of these archetypical POM clusters with missing WO units at positions exposed to bulk solvent and expanded derivatives with additional WO units next to protecting polypeptide segments or other POM clusters. The cryo-EM map, unexpectedly, reveals a POM cluster in the cage center anchored to the wall by a WO linker. Interestingly, distinct POM cluster structures can originate from identical, highly occupied core fragments of three to seven WO units that partly correspond to those found in MoSto loaded with molybdate. These core fragments are firmly bound to the complementary protein template in contrast to the more variable, less occupied residual parts of the visible POM clusters. Due to their higher stability, W-based POM clusters are, on average, larger and more diverse than their Mo-based counterparts.

PubMed: 35779405
DOI: 10.1016/j.jinorgbio.2022.111904

実験手法

X-RAY DIFFRACTION (1.75 Å)