State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
Max Planck Institute for Marine Microbiology, Bremen, Germany.
Nat Microbiol. 2019 Apr;4(4):595-602. doi: 10.1038/s41564-019-0364-2. Epub 2019 Mar 4.
Methanogenesis and anaerobic methane oxidation through methyl-coenzyme M reductase (MCR) as a key enzyme have been suggested to be basal pathways of archaea. How widespread MCR-based alkane metabolism is among archaea, where it occurs and how it evolved remain elusive. Here, we performed a global survey of MCR-encoding genomes based on metagenomic data from various environments. Eleven high-quality mcr-containing metagenomic-assembled genomes were obtained belonging to the Archaeoglobi in the Euryarchaeota, Hadesarchaeota and different TACK superphylum archaea, including the Nezhaarchaeota, Korarchaeota and Verstraetearchaeota. Archaeoglobi WYZ-LMO1 and WYZ-LMO3 and Korarchaeota WYZ-LMO9 encode both the (reverse) methanogenesis and the dissimilatory sulfate reduction pathway, suggesting that they have the genomic potential to couple both pathways in individual organisms. The Hadesarchaeota WYZ-LMO4-6 and Archaeoglobi JdFR-42 encode highly divergent MCRs, enzymes that may enable them to thrive on non-methane alkanes. The occurrence of mcr genes in different archaeal phyla indicates that MCR-based alkane metabolism is common in the domain of Archaea.
产甲烷作用和通过甲基辅酶 M 还原酶 (MCR) 的厌氧甲烷氧化作用被认为是古菌的基本途径。MCR 为基础的烷烃代谢在古菌中是多么普遍，它发生在哪里以及它是如何进化的，这些仍然难以捉摸。在这里，我们基于来自各种环境的宏基因组数据，对 MCR 编码基因组进行了全球调查。获得了 11 个高质量的含有 mcr 的宏基因组组装基因组，它们属于古菌中的古球古菌、热泉古菌和不同的 TACK 超门古菌，包括哪吒古菌、柯拉古菌和斯特雷特古菌。古球古菌 WYZ-LMO1 和 WYZ-LMO3 以及柯拉古菌 WYZ-LMO9 编码（反向）产甲烷作用和异化硫酸盐还原途径，这表明它们具有在单个生物体中耦合这两种途径的基因组潜力。热泉古菌 WYZ-LMO4-6 和古球古菌 JdFR-42 编码高度分化的 MCR，这些酶可能使它们能够在非甲烷烷烃上茁壮成长。mcr 基因在不同古菌门中的存在表明，基于 MCR 的烷烃代谢在古菌域中很常见。
