The multi-layered structure of Dps with a novel di-nuclear ferroxidase center
The multi-layered structure of Dps with a novel di-nuclear ferroxidase center
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DOI：
10.1016/s0022-2836(03)00466-2
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发表时间：
2003-06-06
影响因子：
5.6
通讯作者：
Ladenstein, R
中科院分区：
文献类型：
--
作者：
Ren, B;Tibbelin, G;Ladenstein, R
细胞成分的结晶代表了细菌细胞在应激条件下独特的生存策略。在这样的过程中往往会形成高度有序的层状结构，其中可能涉及一种或多种类型的生物大分子。生物结晶的主要优点归因于它是一个物理过程，因此与能量消耗无关。 Dps 是一种蛋白质，在饥饿的细胞中结晶形成多层结构，以保护 DNA 免受氧化损伤和其他有害因素的影响。首次在没有 DNA 的情况下以原子分辨率揭示了短芽孢杆菌 Dps 蛋白的多层晶体结构。对结构的检查为双核亚铁氧化酶中心的存在提供了第一个直接证据，该中心在迄今为止发现的所有双铁蛋白中具有独特的特征。它构成了结晶态和溶液中 Dps 亚铁氧化酶活性的结构基础。这一发现证明金属离子解毒的酶促过程可能对DNA造成严重的氧化损伤，是Dps防御机制的另一个重要方面。在多层结构中，Dps十二聚体以高度有序的方式组织。它们在结构的每一层都采用了经典的六角形堆积形式。这种排列产生了增强的结构特征，有利于从环境中吸引和吸收金属离子。高度有序的层状结构可以为层间DNA的容纳提供理想的基础，从而使其在应激条件下能够被隔离并免受有害因素的影响。 (C) 2003 Elsevier Science Ltd. 保留所有权利。
The crystallization of cellular components represents a unique survival strategy for bacterial cells under stressed conditions. A highly ordered, layered structure is often formed in such a process, which may involve one or more than one type of bio-macromolecules. The main advantage of biocrystallization has been attributed to the fact that it is a physical process and thus is independent of energy consumption. Dps is a protein that crystallizes to form a multi-layered structure in starved cells in order to protect DNA against oxidative damage and other detrimental factors. The multi-layered crystal structure of a Dps protein from Bacillus brevis has been revealed for the first time at atomic resolution in the absence of DNA. Inspection of the structure provides the first direct evidence for the existence of a di-nuclear ferroxidase center, which possesses unique features among all the di-iron proteins identified so far. It constitutes the structural basis for the ferroxidase activity of Dps in the crystalline state as well as in solution. This finding proves that the enzymatic process of detoxification of metal ions, which may cause severe oxidative damage to DNA, is the other important aspect of the defense mechanism performed by Dps. In the multi-layered structure, Dps dodecamers are organized in a highly ordered manner. They adopt the classic form of hexagonal packing in each layer of the structure. Such arrangement results in reinforced structural features that would facilitate the attraction and absorption of metal ions from the environment. The highly ordered layered structure may provide an ideal basis for the accommodation of DNA between the layers so that it can be isolated and protected from harmful factors under stress conditions. (C) 2003 Elsevier Science Ltd. All rights reserved.