Wang Yinzhao, Wegener Gunter, Williams Tom A, Xie Ruize, Hou Jialin, Wang Fengping, Xiao Xiang
State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Sci Adv. 2021 Feb 10;7(7). doi: 10.1126/sciadv.abd7180. Print 2021 Feb.
Methanogens are considered as one of the earliest life forms on Earth, and together with anaerobic methane-oxidizing archaea, they have crucial effects on climate stability. Yet, the origin and evolution of anaerobic alkane metabolism in the domain Archaea remain controversial. Here, we show that methanogenesis was already present in the common ancestor of Euryarchaeota, TACK archaea, and Asgard archaea likely in the late Hadean or early Archean eon and that the ancestral methanogen was dependent on methylated compounds and hydrogen. Carbon dioxide-reducing methanogenesis developed later through the evolution of tetrahydromethanopterin -methyltransferase, which linked methanogenesis to the Wood-Ljungdahl pathway for energy conservation. Multicarbon alkane metabolisms in Archaea also originated early, with genes coding for the activation of short- or even long-chain alkanes likely evolving from an ethane-metabolizing ancestor. These genes were likely horizontally transferred to multiple archaeal clades including () Bathyarchaeota, Helarchaeota, Hadesarchaeota, and the methanogenic Methanoliparia.
产甲烷菌被认为是地球上最早的生命形式之一，它们与厌氧甲烷氧化古菌一起，对气候稳定性有着至关重要的影响。然而，古菌域中厌氧烷烃代谢的起源和进化仍存在争议。在这里，我们表明产甲烷作用可能在冥古宙晚期或太古宙早期就已存在于广古菌门、TACK古菌和阿斯加德古菌的共同祖先中，并且原始产甲烷菌依赖于甲基化化合物和氢气。通过四氢甲蝶呤-甲基转移酶的进化，后来发展出了二氧化碳还原产甲烷作用，该酶将产甲烷作用与用于能量保存的伍德-Ljungdahl途径联系起来。古菌中的多碳烷烃代谢也起源较早，编码短链甚至长链烷烃激活的基因可能从一个代谢乙烷的祖先进化而来。这些基因可能通过水平转移到多个古菌分支，包括（）嗜温栖热菌、嗜热栖热菌、冥古菌，以及产甲烷的甲醇脂菌。
