Bacteria and Eukarya have cell membranes with sn-glycerol-3-phosphate (G3P), whereas archaeal membranes contain sn-glycerol-1-phosphate (G1P). Determining the time at which cells with either G3P-lipid membranes or G1P-lipid membranes appeared is important for understanding the early evolution of terrestrial life. To clarify this issue, we reconstructed molecular phylogenetic trees of G1PDH (G1P dehydrogenase; EgsA/AraM) which is responsible for G1P synthesis and G3PDHs (G3P dehydrogenase; GpsA and GlpA/GlpD) and glycerol kinase (GlpK) which is responsible for G3P synthesis. Together with the distribution of these protein-encoding genes among archaeal and bacterial groups, our phylogenetic analyses suggested that GlpA/GlpD in the Commonote (the last universal common ancestor of all extant life with a cellular form, Commonote commonote) acquired EgsA (G1PDH) from the archaeal common ancestor (Commonote archaea) and acquired GpsA and GlpK from a bacterial common ancestor (Commonote bacteria). In our scenario based on this study, the Commonote probably possessed a G3P-lipid membrane synthesized enzymatically, after which the archaeal lineage acquired G1PDH followed by the replacement of a G3P-lipid membrane with a G1P-lipid membrane.

中文翻译：

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古细菌细胞的诞生：G1P脱氢酶，G3P脱氢酶和甘油激酶的分子系统发育分析提示具有G1P极性脂质的古细菌膜的衍生特征。

细菌和Eukarya的细胞膜上都带有Sn-甘油-3-磷酸酯（G3P），而古细菌膜上则含有sn-甘油-1-磷酸酯（G1P）。确定具有G3P-脂质膜或G1P-脂质膜的细胞出现的时间对于了解地球生命的早期进化很重要。为了澄清这个问题，我们重建了负责G1P合成的G1PDH（G1P脱氢酶； EgsA / AraM）和G3PDHs（G3P脱氢酶； GpsA和GlpA / GlpD）和负责G3P合成的甘油激酶（GlpK）的分子系统树。 。结合这些蛋白质编码基因在古细菌群和细菌群之间的分布，我们的系统进化分析表明，在普通体（所有现存生命中最后一个具有细胞形态的普通共同体，普通体平民）的GlpA / GlpD获得了EgsA（G1PDH）来自古细菌的共同祖先（Commonote archaea），并从细菌共同祖先（Commonote细菌）获得GpsA和GlpK 。在基于这项研究的方案中，Commonote可能具有酶促合成的G3P-脂质膜，此后古菌谱系获得了G1PDH，然后用G1P-脂质膜替代了G3P-脂质膜。