Institute for Microbiology and Archaeal Center, Regensburg University, Regensburg, Germany
Institute for Microbiology and Archaeal Center, Regensburg University, Regensburg, Germany.
J Bacteriol. 2019 Mar 13;201(7). doi: 10.1128/JB.00510-18. Print 2019 Apr 1.
In this study, the ATP synthase of was purified, characterized, and structurally compared to the respective enzymes of the other species, to shed light on energy conservation in this unique group of archaea. The crenarchaeal genus comprises three described species, i.e., and from hot marine sediments near Iceland and from a hydrothermal vent system in the Pacific Ocean. This genus is unique among all archaea due to the unusual cell envelope, consisting of two membranes that enclose a large intermembrane compartment (IMC). is the best studied member of this genus, mainly because it is the only known host for the potentially parasitic archaeon grows chemolithoautotrophically, and its sole energy-yielding reaction is the reduction of elemental sulfur with molecular hydrogen, forming large amounts of hydrogen sulfide. This reaction generates an electrochemical gradient, which is used by the ATP synthase, located in the outer cellular membrane, to generate ATP inside the IMC. The genome of encodes nine subunits of an A-type ATP synthase, which we could identify in the purified complex. Although the maximal activity of the enzyme was measured around pH 6, the optimal stability of the AA complex seemed to be at pH 9. Interestingly, the soluble A subcomplexes of the different species exhibited significant differences in their apparent molecular masses in native electrophoresis, although their behaviors in gel filtration and chromatography-mass spectrometry were very similar. The represent one of the major phyla within the domain. This study describes the successful purification of a crenarchaeal ATP synthase. To date, all information about A-type ATP synthases is from euryarchaeal enzymes. The fact that it has not been possible to purify this enzyme complex from a member of the until now points to significant differences in stability, possibly caused by structural alterations. Furthermore, the study subject has a particular importance among crenarchaeotes, since it is the only known host of The energy metabolism in this system is still poorly understood, and our results can help elucidate the unique relationship between these two microbes.
在这项研究中，纯化了 中的 ATP 合酶，对其进行了表征，并与其他 种的相应酶进行了结构比较，以期阐明这个独特的古菌群体中的能量守恒机制。古菌属 由三个已描述的种组成，即来自冰岛附近热海洋沉积物的 和 ，以及来自太平洋热液喷口系统的 。由于其独特的细胞膜结构，该属在所有古菌中都是独一无二的，其细胞膜由两层组成，包围着一个大的膜间腔（intermembrane compartment，IMC）。 是该属中研究最充分的成员，主要是因为它是潜在寄生古菌 的唯一已知宿主。 能够化能自养生长，其唯一的产能反应是用分子氢还原元素硫，形成大量的硫化氢。这种反应产生电化学梯度，该梯度被位于外细胞膜中的 ATP 合酶利用，在 IMC 内部生成 ATP。 的基因组编码了一个 A 型 ATP 合酶的九个亚基，我们可以在纯化的复合物中识别出这些亚基。尽管 酶的最大 活性是在 pH6 左右测量的，但 AA 复合物的最佳稳定性似乎在 pH9。有趣的是，不同 种的可溶性 A 亚基在天然电泳中的表观分子量有显著差异，尽管它们在凝胶过滤和色谱-质谱分析中的行为非常相似。 代表了 域中的主要门之一。本研究描述了一种古菌 ATP 合酶的成功纯化。到目前为止，所有关于 A 型 ATP 合酶的信息都来自于广古菌酶。到目前为止，还没有从 属的成员中纯化出这种酶复合物，这一事实表明其稳定性可能存在显著差异，这可能是由于结构改变所致。此外，研究对象 在泉古菌中具有特殊的重要性，因为它是 的唯一已知宿主。这个系统的能量代谢仍然知之甚少，我们的研究结果可以帮助阐明这两个微生物之间的独特关系。
