DsrL Mediates Electron Transfer between NADH and rDsrAB in Allochromatium vinosum.
DsrL Mediates Electron Transfer between NADH and rDsrAB in Allochromatium vinosum.
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DOI：
10.1111/1462-2920.14899
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发表时间：
2019-12
影响因子：
5.1
通讯作者：
Maria Löffler;Julia Feldhues;S. Venceslau;Lydia Kammler;Fabian Grein;I. Pereira;C. Dahl
中科院分区：
文献类型：
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作者：
Maria Löffler;Julia Feldhues;S. Venceslau;Lydia Kammler;Fabian Grein;I. Pereira;C. Dahl
异化亚硫酸盐还原酶DsrAB存在于硫酸盐/亚硫酸盐还原原核生物中，存在于硫还原剂中，也存在于硫氧化剂中，在那里它起相反的作用。宏基因组研究中依赖于dsrAB、其他dsr基因或其组合的存在的生理性状的预测遭受缺乏关于关键Dsr蛋白的信息。铁-硫黄素蛋白DsrL是这类蛋白的一个例子。它在硫氧化过程中具有记录的基本功能，最近也在一些可能的硫酸盐和亚硫酸盐还原剂的宏基因组中发现。在这里，我们表明，DsrL和反向作用rDsrAB可以形成一个复杂的，并共同纯化的光养硫氧化剂Allochromatium vinosum。重组DsrL表现出NAD（P）H：受体氧化还原酶活性，对NADH的偏好强于NADPH。在体外，rDsrABL复合物有效地催化NADH依赖的亚硫酸盐还原，这是强烈增强的硫结合蛋白Dsrc。我们的工作揭示了NAD+作为合适的体内电子受体硫氧化的有机体中运行的rDsr途径，并指出减少烟酰胺腺嘌呤二核苷酸作为电子供体的硫酸盐/亚硫酸盐还原原核生物，含有DsrL的亚硫酸盐还原。此外，在宏基因组研究中，dsrL不能用作区分硫酸盐/亚硫酸盐还原剂和硫氧化剂的标记物而无需进一步分析。本文受版权保护。All rights reserved.
Dissimilatory sulfite reductase DsrAB occurs in sulfate/sulfite-reducing prokaryotes, in sulfur disproportionators and also in sulfur oxidizers, where it functions in reverse. Predictions of physiological traits in metagenomic studies relying on the presence of dsrAB, other dsr genes or combinations thereof suffer from the lack of information on crucial Dsr proteins. The iron-sulfur flavoprotein DsrL is an example of this group. It has a documented essential function during sulfur oxidation and was recently also found in some metagenomes of probable sulfate and sulfite reducers. Here, we show that DsrL and reverse acting rDsrAB can form a complex and are co-purified from the phototrophic sulfur oxidizer Allochromatium vinosum. Recombinant DsrL exhibits NAD(P)H:acceptor oxidoreductase activity with a strong preference for NADH over NADPH. In vitro, the rDsrABL complex effectively catalyzes NADH-dependent sulfite reduction, which is strongly enhanced by the sulfur-binding protein DsrC. Our work reveals NAD+ as suitable in vivo electron acceptor for sulfur oxidation in organisms operating the rDsr pathway, and points to reduced nicotinamide adenine dinucleotides as electron donors for sulfite reduction in sulfate/sulfite-reducing prokaryotes that contain DsrL. In addition, dsrL cannot be used as a marker distinguishing sulfate/sulfite reducers and sulfur oxidizers in metagenomic studies without further analysis. This article is protected by copyright. All rights reserved.