Organohalide respiratory chains: composition, topology and key enzymes
Organohalide respiratory chains: composition, topology and key enzymes
复制标题
DOI：
10.1093/femsec/fiy035
复制
发表时间：
2018-04
影响因子：
4.2
通讯作者：
T. Schubert;L. Adrian;G. Sawers;G. Diekert
中科院分区：
文献类型：
--
作者：
T. Schubert;L. Adrian;G. Sawers;G. Diekert
利用卤化有机化合物作为终端电子受体，将系统发育多样化的有机卤化物呼吸细菌与其他主要使用硝酸盐、富马酸盐、硫酸盐或氧化金属的呼吸厌氧细菌区分开来。有机卤化物呼吸作用的独特之处在于，它招募了一种含铁硫的钴化物蛋白，即胞外膜结合的还原脱卤酶，作为电子传递链中的末端还原酶。近年来，人们对有机卤化物呼吸细菌中电子转移路径与化学渗透机理的理解做出了重大贡献。呼吸性和非呼吸性还原脱卤酶的结构分析揭示了分子内电子通过两个立方铁硫簇转移到活性位点的钴化物。根据是否涉及醌类，确定了两种分子间电子转移链，它们的组成和质子易位方式不同。事实上，各种呼吸链结构已经被揭示，并提出了不同假设耦合机制的证据。在麦卡蒂脱盐coccoides mccartyi菌株CBDB1中发现了一种多酶呼吸复合体，该复合体结合了摄取氢化酶、铁硫钼酶复合体和还原脱halogenase，这为这些神秘微生物的能量保存模式提出了新的问题。在这篇小型综述中，我们强调了这些发现，并对潜在的未来发展进行了展望。数字。没有可用的标题。
Abstract The utilization of halogenated organic compounds as terminal electron acceptors separates the phylogenetically diverse organohalide‐respiring bacteria from other respiratory anaerobes that predominantly use nitrate, fumarate, sulfate or oxidized metals. Organohalide respiration is unique in recruiting a cobamide‐containing iron‐sulfur protein, the extracellular membrane‐bound reductive dehalogenase, as terminal reductase in the electron transfer chain. In recent years substantial contributions have been made to the understanding of how electron transfer paths couple mechanistically to chemiosmosis in the organohalide‐respiring bacteria. The structural analysis of a respiratory and a non‐respiratory reductive dehalogenase revealed the intramolecular electron transfer via two cubane iron‐sulfur clusters to the cobamide at the active site. Based on whether quinones are involved, two types of intermolecular electron transfer chains have been identified, which differ in their composition and mode of proton translocation. Indeed, various respiratory chain architectures have been unraveled and evidence for different putative coupling mechanisms presented. The identification of a multienzyme respiratory complex that combines uptake hydrogenase, a complex iron‐sulfur molybdoenzyme and a reductive dehalogenase in Dehalococcoides mccartyi strain CBDB1 has raised new questions regarding the mode of energy conservation in these enigmatic microbes. In this mini‐review, we highlight these findings and provide an outlook on potential future developments. Figure. No Caption available.