Crystal structure of the [2Fe-2S] protein I (Shethna protein I) from Azotobacter vinelandii.
Crystal structure of the [2Fe-2S] protein I (Shethna protein I) from Azotobacter vinelandii.
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DOI：
10.1107/s2053230x21009936
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发表时间：
2021-11-01
期刊：
影响因子：
--
通讯作者：
Murray JW
中科院分区：
文献类型：
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作者：
Kabasakal BV;Cotton CAR;Murray JW
几种固氮菌铁硫蛋白可能在固氮菌固氮时必须维持的复杂氧化还原化学中发挥作用。棕色固氮菌[2Fe-2S]蛋白I（Shethna蛋白I）的2.1μ m分辨率晶体结构揭示了与风产液菌硫氧还蛋白样[2Fe-2S]蛋白结构相似的同源二聚体，其中[2Fe-2S]簇由周围保守的半胱氨酸残基配位。 棕色固氮菌是一种典型的固氮菌，是结构和生物化学工作中大多数固氮酶材料的来源。固氮菌可以在高于大气水平的氧气中生长，尽管固氮酶活性对氧气敏感。固氮菌在其基因组中有许多铁硫蛋白，这些蛋白早在20世纪60年代就被发现，可能在固氮菌在固氮时必须保持的复杂氧化还原化学中发挥作用。在这里，2.1 μ m分辨率的晶体结构的[2Fe-2S]蛋白I（Shethna蛋白I）从A。 vinelandii的，揭示了一个同源二聚体与周围的保守的半胱氨酸残基协调的[2Fe-2S]簇。它与来自风产液囊菌的硫氧还蛋白样[2Fe-2S]蛋白的结构相似，包括[2Fe-2S]簇的位置和保守的半胱氨酸残基。Shethna蛋白I的结构将为理解其固氮功能及其与其他铁氧还蛋白的进化关系提供信息。
Several Azotobacter iron–sulfur proteins probably play roles in the complex redox chemistry that Azotobacter must maintain when fixing nitrogen. The 2.1 Å resolution crystal structure of the [2Fe–2S] protein I (Shethna protein I) from Azotobacter vinelandii reveals a homodimer similar to the structure of the thioredoxin-like [2Fe–2S] protein from Aquifex aeolicus, with the [2Fe–2S] cluster coordinated by the surrounding conserved cysteine residues. Azotobacter vinelandii is a model diazotroph and is the source of most nitrogenase material for structural and biochemical work. Azotobacter can grow in above-atmospheric levels of oxygen, despite the sensitivity of nitrogenase activity to oxygen. Azotobacter has many iron–sulfur proteins in its genome, which were identified as far back as the 1960s and probably play roles in the complex redox chemistry that Azotobacter must maintain when fixing nitrogen. Here, the 2.1 Å resolution crystal structure of the [2Fe–2S] protein I (Shethna protein I) from A. vinelandii is presented, revealing a homodimer with the [2Fe–2S] cluster coordinated by the surrounding conserved cysteine residues. It is similar to the structure of the thioredoxin-like [2Fe–2S] protein from Aquifex aeolicus, including the positions of the [2Fe–2S] clusters and conserved cysteine residues. The structure of Shethna protein I will provide information for understanding its function in relation to nitrogen fixation and its evolutionary relationships to other ferredoxins.