Solar powered biohydrogen production requires specific localization of the hydrogenase.
Solar powered biohydrogen production requires specific localization of the hydrogenase.
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DOI：
10.1039/c4ee02502d
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发表时间：
2014-10-15
影响因子：
32.5
通讯作者：
Bryan SJ
中科院分区：
文献类型：
--
作者：
Burroughs NJ;Boehm M;Eckert C;Mastroianni G;Spence EM;Yu J;Nixon PJ;Appel J;Mullineaux CW;Bryan SJ
蓝藻氢酶的亚细胞定位受生理控制，对光合产氢至关重要。蓝细菌含有双向[NiFe]氢化酶，其在缺氧细胞暴露于光时瞬时产生氢，潜在地充当从电子传递链释放过量电子的“阀”。然而，它与光合电子传递链的相互作用仍不清楚。通过GFP标记的HoxF心肌黄酶亚基，我们表明，氢化酶是类囊体相关的，包括一个人口分散均匀通过类囊体和一个亚群本地化离散点在远端类囊体。类囊体定位的HoxH和HoxY氢化酶亚基的免疫金电子显微镜证实。心肌黄酶HoxE亚基是必不可少的招聘分散的类囊体人口，可能锚定的氢化酶的膜，但聚集点发生通过一个独特的HoxE独立的机制。膜结合不需要NDH-1。本地化是动态的分钟尺度上，缺氧和高光诱导这些人口之间的显着重新分配，有利于斑点。由于HoxE是必不可少的访问其电子供体，电子供应的氢化酶依赖于生理控制的本地化，潜在地提供了一个新的途径，以提高光合氢的生产，通过利用本地化/聚集信号。
Subcellular localization of the cyanobacterial hydrogenase is under physiological control and is crucial for photosynthetic hydrogen production. Cyanobacteria contain a bidirectional [NiFe] hydrogenase which transiently produces hydrogen upon exposure of anoxic cells to light, potentially acting as a “valve” releasing excess electrons from the electron transport chain. However, its interaction with the photosynthetic electron transport chain remains unclear. By GFP-tagging the HoxF diaphorase subunit we show that the hydrogenase is thylakoid associated, comprising a population dispersed uniformly through the thylakoids and a subpopulation localized to discrete puncta in the distal thylakoid. Thylakoid localisation of both the HoxH and HoxY hydrogenase subunits is confirmed by immunogold electron microscopy. The diaphorase HoxE subunit is essential for recruitment to the dispersed thylakoid population, potentially anchoring the hydrogenase to the membrane, but aggregation to puncta occurs through a distinct HoxE-independent mechanism. Membrane association does not require NDH-1. Localization is dynamic on a scale of minutes, with anoxia and high light inducing a significant redistribution between these populations in favour of puncta. Since HoxE is essential for access to its electron donor, electron supply to the hydrogenase depends on a physiologically controlled localization, potentially offering a new avenue to enhance photosynthetic hydrogen production by exploiting localization/aggregation signals.