A phylogenetically novel cyanobacterium most closely related to Gloeobacter
A phylogenetically novel cyanobacterium most closely related to Gloeobacter
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DOI：
10.1038/s41396-020-0668-5
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发表时间：
2020-05-18
期刊：
影响因子：
11
通讯作者：
Jungblut, Anne D.
中科院分区：
文献类型：
--
作者：
Grettenberger, Christen L.;Sumner, Dawn Y.;Jungblut, Anne D.
产生产氧光合作用创新的进化步骤的线索可能保存在非光合作用Vampirovibrionia（以前的Melainabacteria）和含类囊体的蓝藻之间的生物基因组中。然而，只有两个物种与已公布的基因组已知占据这个系统发育的空间，都在属Gloeplum。在这里，我们描述了几乎完整的，宏基因组组装的基因组（MAG）的未培养的生物体，遗传学上放置在Gloegalus附近，我们提出的名称Aurora vandensis {Au'ro. ra。L.阴性. n.奥罗拉，罗马神话中的黎明女神; van.de 'nsis。N.L.阴性.南极洲旺达湖（Lake Vanda，Antarctica）A的MAG。vandensis含有含氧光合作用所必需的大多数基因的同源物，包括关键反应中心蛋白。许多附属亚基与光系统在其他物种中要么是失踪的MAG或保守性差。MAG还缺乏与色素藻蓝红蛋白、藻红蛋白和藻胆体的几个结构部分相关的基因的同源物。这种生物体的其他特征预计将告知模型的进化产氧光合作用。
Clues to the evolutionary steps producing innovations in oxygenic photosynthesis may be preserved in the genomes of organisms phylogenetically placed between non-photosynthetic Vampirovibrionia (formerly Melainabacteria) and the thylakoid-containing Cyanobacteria. However, only two species with published genomes are known to occupy this phylogenetic space, both within the genus Gloeobacter. Here, we describe nearly complete, metagenome-assembled genomes (MAGs) of an uncultured organism phylogenetically placed near Gloeobacter, for which we propose the name Candidatus Aurora vandensis {Au'ro.ra. L. fem. n. aurora, the goddess of the dawn in Roman mythology; van.de'nsis. N.L. fem. adj. vandensis of Lake Vanda, Antarctica}. The MAG of A. vandensis contains homologs of most genes necessary for oxygenic photosynthesis including key reaction center proteins. Many accessory subunits associated with the photosystems in other species either are missing from the MAG or are poorly conserved. The MAG also lacks homologs of genes associated with the pigments phycocyanoerethrin, phycoeretherin and several structural parts of the phycobilisome. Additional characterization of this organism is expected to inform models of the evolution of oxygenic photosynthesis.