2Z7E

Crystal structure of Aquifex aeolicus IscU with bound [2Fe-2S] cluster

2Z7E の概要

• エントリーDOI: 10.2210/pdb2z7e/pdb
• 分子名称: NifU-like protein, SULFATE ION, FE2/S2 (INORGANIC) CLUSTER, ... (4 entities in total)
• 機能のキーワード: iron-sulfur cluster, iron, biosynthesis, [2fe-2s], isc, iscu, nifu, asymmetric trimer, three conserved cys, biosynthetic protein
• 由来する生物種: Aquifex aeolicus
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 53071.46

構造登録者

Shimomura, Y.,Wada, K.,Takahashi, Y.,Fukuyama, K. (登録日: 2007-08-20, 公開日: 2008-08-19, 最終更新日: 2024-10-30)

主引用文献

Shimomura, Y.,Wada, K.,Fukuyama, K.,Takahashi, Y.
The asymmetric trimeric architecture of [2Fe-2S] IscU: implications for its scaffolding during iron-sulfur cluster biosynthesis
J.Mol.Biol., 383:133-143, 2008

PubMed Abstract: IscU is a key component of the ISC machinery and is involved in the biogenesis of iron-sulfur (Fe-S) proteins. IscU serves as a scaffold for assembly of a nascent Fe-S cluster prior to its delivery to an apo protein. Here, we report the first crystal structure of IscU with a bound [2Fe-2S] cluster from the hyperthermophilic bacterium Aquifex aeolicus, determined at a resolution of 2.3 A, using multiwavelength anomalous diffraction of the cluster. The holo IscU formed a novel asymmetric trimer that harbored only one [2Fe-2S] cluster. One iron atom of the cluster was coordinated by the S(gamma) atom of Cys36 and the N(epsilon) atom of His106, and the other was coordinated by the S(gamma) atoms of Cys63 and Cys107 on the surface of just one of the protomers. However, the cluster was buried inside the trimer between the neighboring protomers. The three protomers were conformationally distinct from one another and associated around a noncrystallographic pseudo-3-fold axis. The three flexible loop regions carrying the ligand-binding residues (Cys36, Cys63, His106 and Cys107) and the N-terminal alpha1 helices were positioned at the interfaces and underwent substantial conformational rearrangement, which stabilized the association of the asymmetric trimer. This unique trimeric A. aeolicus holo-IscU architecture was clearly distinct from other known monomeric apo-IscU/SufU structures, indicating that asymmetric trimer organization, as well as its association/dissociation, would be involved in the scaffolding function of IscU.

PubMed: 18723024
DOI: 10.1016/j.jmb.2008.08.015

実験手法

X-RAY DIFFRACTION (2.3 Å)