Crystal structure of Escherichia coli Fdx, an adrenodoxin-type ferredoxin involved in the assembly of iron-sulfur clusters
Crystal structure of Escherichia coli Fdx, an adrenodoxin-type ferredoxin involved in the assembly of iron-sulfur clusters
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DOI：
10.1021/bi010544t
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发表时间：
2001-09-18
期刊：
影响因子：
2.9
通讯作者：
Fukuyama, K
中科院分区：
文献类型：
--
作者：
Kakuta, Y;Horio, T;Fukuyama, K
大肠杆菌铁氧还蛋白 (Fdx) 是一种肾上腺氧还蛋白型 [2Fe-2S] 铁氧还蛋白。最近的遗传分析表明，它在各种铁硫 (Fe-S) 蛋白的成熟中具有重要作用。 Fdx 可能是负责 Fe-S 簇生物发生的复杂机制的一个组成部分。其晶体结构通过多波长反常色散法利用蛋白质[2Fe-2S]簇中的铁原子测定，然后在1.7埃分辨率下精修至R和无R值分别为0.255和0.278。 Fdx的结构与牛肾上腺素还蛋白(Adx)和恶臭假单胞菌恶臭氧还蛋白(Pdx)的结构相似，其相应的Cα原子的均方根偏差分别为1.8和2.2埃。该分析还揭示了伸入溶剂中的 C 末端残基的结构，而 Adx 和 Pdx 中缺少这种结构。 [2Fe-2S]簇位于分子边缘，与Cys42、Cys48、Cys51和Cys87的S伽马原子键合。静电势分析表明，Fdx 的表面有两个带负电的区域，由疏水泳道隔开。其中一个保留在 Adx 表面，这是与肾上腺氧还蛋白还原酶相互作用的区域。 Cys46位于分子表面[2Fe-2S]簇附近，这表明它可能参与Fe-S簇的形成。
Escherichia coli ferredoxin (Fdx) is an adrenodoxin-type [2Fe-2S] ferredoxin. Recent genetic analyses show that it has an essential role in the maturation of various iron-sulfur (Fe-S) proteins. Fdx probably functions as a component of the complex machinery responsible for the biogenesis of Fe-S clusters. Its crystal structure was determined by the multiple-wavelength anomalous dispersion method using the iron atoms in the [2Fe-2S] cluster of the protein and then refined to R and R-free values of 0.255 and 0.278, respectively, at 1.7 Angstrom resolution. The structure of Fdx is similar to the structures of bovine adrenodoxin (Adx) and Pseudomonas putida putidaredoxin (Pdx) whose respective root-mean-square deviations of the corresponding C alpha atoms are 1.8 and 2.2 Angstrom. This analysis also revealed the structure of the C-terminal residues protruding into the solvent, which is missing in Adx and Pdx. The [2Fe-2S] cluster is located at the edge of the molecule and bonds with the S gamma atoms of Cys42, Cys48, Cys51, and Cys87. Electrostatic potential analysis showed that the surface of Fdx has two negatively charged areas separated by a hydrophobic lane. One is conserved on the surface of Adx which is an area of interaction with adrenodoxin reductase. Cys46 is located on the molecular surface in the vicinity of the [2Fe-2S] cluster, an indication that it may be involved in Fe-S cluster formation.