Recombinant RquA catalyzes the in vivo conversion of ubiquinone to rhodoquinone in Escherichia coli and Saccharomyces cerevisiae
Recombinant RquA catalyzes the in vivo conversion of ubiquinone to rhodoquinone in Escherichia coli and Saccharomyces cerevisiae
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DOI：
10.1016/j.bbalip.2019.05.007
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发表时间：
2019-09-01
影响因子：
4.8
通讯作者：
Shepherd, Jennifer N.
中科院分区：
文献类型：
--
作者：
Bernert, Ann C.;Jacobs, Evan J.;Shepherd, Jennifer N.
萜类醌类化合物是脂溶性氧化还原活性化合物，是必需的电子载体和抗氧化剂。其中一种苯二酚，罗多酚(RQ)，将呼吸电子转移链偶联到富马酸的还原上，以促进无氧呼吸。这一机制允许RQ合成生物使用富马酸作为最终电子受体来操作他们的呼吸链。RQ的生物合成仅限于少数原核生物和真核生物，这一生物合成途径的细节仍然是个谜。在红色红螺菌中发现了一个基因rquA，它是RQ生物合成所必需的。然而，基因产物RquA的功能仍不清楚。在这里，我们使用反向遗传学的方法，我们证明了RquA直接将泛醌转化为RQ。我们还展示了在体内首次在大肠杆菌和酿酒酵母中合成RQ，这两种生物本身并不产生RQ。这些发现有助于阐明含有RquA同源物的物种中完整的RQ生物合成途径。
Terpenoid quinones are liposoluble redox-active compounds that serve as essential electron carriers and antioxidants. One such quinone, rhodoquinone (RQ), couples the respiratory electron transfer chain to the reduction of fumarate to facilitate anaerobic respiration. This mechanism allows RQ-synthesizing organisms to operate their respiratory chain using fumarate as a final electron acceptor. RQ biosynthesis is restricted to a handful of prokaryotic and eukaryotic organisms, and details of this biosynthetic pathway remain enigmatic. One gene, rquA, was discovered to be required for RQ biosynthesis in Rhodospirillum rubrum. However, the function of the gene product, RquA, has remained unclear. Here, using reverse genetics approaches, we demonstrate that RquA converts ubiquinone to RQ directly. We also demonstrate the first in vivo synthetic production of RQ in Escherichia coli and Saccharomyces cerevisiae, two organisms that do not natively produce RQ. These findings help clarify the complete RQ biosynthetic pathway in species which contain RquA homologs.