NmPin from the marine thaumarchaeote Nitrosopumilus maritimus is an active membrane associated prolyl isomerase.
NmPin from the marine thaumarchaeote Nitrosopumilus maritimus is an active membrane associated prolyl isomerase.
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DOI：
10.1186/s12915-016-0274-1
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发表时间：
2016-06-27
期刊：
影响因子：
5.4
通讯作者：
Bayer P
中科院分区：
文献类型：
--
作者：
Hoppstock L;Trusch F;Lederer C;van West P;Koenneke M;Bayer P
肽基脯氨酰异构酶（PPIases）存在于所有生命形式中，在蛋白质折叠和调节中起着至关重要的作用。它们催化许多蛋白质中脯氨酸残基之前的肽键的顺反异构化。小蛋白是PPIases的一个家族，在一些真核生物中已被广泛研究。然而，对它们在古细菌中的表达、功能和定位却知之甚少。在这里，我们描述的内源性表达，分子结构，功能和细胞定位的NmPin，一个单域小蛋白型PPIase从海栖亚硝化菌。这种海洋化能自养古菌属于全球丰富的Thaumarchaeota门。使用高分辨率NMR光谱，我们证明了NmPin的3D结构采用小蛋白折叠，并通过蛋白酶偶联测定和诱变研究证实了其肽基脯氨酰异构酶活性。详细的拓扑分析揭示了一个带正电荷的赖氨酸丰富的补丁的蛋白质表面上，这是保守的所有已知的小蛋白序列的thaumarchaeotes和目标NmPin的脂质在体外。免疫荧光显微镜证实，该蛋白质附着在体内的古细菌细胞外膜。透射电子显微镜观察发现NmPin在细胞膜表面均匀分布，这与原核生物的天然细胞形状有关。我们提出了一种新的催化活性thaumarchaeal小蛋白的溶液结构。我们的研究结果表明，一个赖氨酸丰富的补丁在NmPin介导的膜定位。这些发现提供了一个模型，其中NmPin位于古菌膜和表面层之间，因此建议S层的蛋白质作为这种小蛋白的关键靶底物。本文的在线版本（doi：10.1186/s12915-016-0274-1）包含补充材料，可供授权用户使用。
Peptidyl-prolyl isomerases (PPIases) are present in all forms of life and play a crucial role in protein folding and regulation. They catalyze the cis-trans isomerization of the peptide bond that precedes proline residues in numerous proteins. The parvulins, which is one family of PPIases, have been extensively investigated in several eukaryotes. However, nothing is known about their expression, function and localization in archaea. Here, we describe the endogenous expression, molecular structure, function and cellular localization of NmPin, a single-domain parvulin-type PPIase from Nitrosopumilus maritimus. This marine chemolithoautotrophic archaeon belongs to the globally abundant phylum Thaumarchaeota. Using high resolution NMR spectroscopy we demonstrate that the 3D structure of NmPin adopts a parvulin fold and confirmed its peptidyl-prolyl isomerase activity by protease-coupled assays and mutagenesis studies. A detailed topological analysis revealed a positively charged lysine-rich patch on the protein surface, which is conserved in all known parvulin sequences of thaumarchaeotes and targets NmPin to lipids in vitro. Immunofluorescence microscopy confirms that the protein is attached to the outer archaeal cell membrane in vivo. Transmission electron microscopy uncovered that NmPin has a uniform distribution at the membrane surface, which is correlated with a native cell shape of the prokaryote. We present a novel solution structure of a catalytically active thaumarchaeal parvulin. Our results reveal that a lysine-rich patch in NmPin mediates membrane localization. These findings provide a model whereby NmPin is located between the archaeal membrane and the surface layer and hence suggest proteins of the S-layer as the key target substrates of this parvulin. The online version of this article (doi:10.1186/s12915-016-0274-1) contains supplementary material, which is available to authorized users.