MmcA is an electron conduit that facilitates both intracellular and extracellular electron transport in Methanosarcina acetivorans.
MmcA is an electron conduit that facilitates both intracellular and extracellular electron transport in Methanosarcina acetivorans.
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MmcA 是一种电子导管，可促进乙酸甲烷八叠球菌的细胞内和细胞外电子传输。
DOI：
10.1101/2023.04.20.537704
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Nayak,DiptiD
中科院分区：
文献类型：
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作者：
Gupta,Dinesh;Chen,Keying;Elliott,SeanJ;Nayak,DiptiD
产甲烷菌是一组多样的甲烷菌，它们强制性地将能量守恒与甲烷的产生相结合。一些产甲烷菌编码能量保存的替代途径，如厌氧呼吸，但这个过程的生化细节是未知的。我们发现，多血红素型细胞色素MmcA从醋酸甲烷八叠球菌甲烷生成过程中的细胞内电子传递的重要性，也可以减少胞外电子受体，如可溶性铁3+和蒽醌-2，6-二磺酸。与这些观察结果一致，MmcA显示可逆氧化还原特征，范围为−100至−450 mV（相对于SHE）。此外，缺乏mmcA的突变体具有显著较慢的Fe 3+还原速率。ThemmcA基因座是普遍存在于成员的订单Methanacinalesand是一个独特的分支的多血红素细胞色素的一部分，密切相关的octaheme四硫酸还原酶。总之，MmcA可能作为一个电子导管，可以潜在地支持各种能源节约战略，延伸到甲烷。
Methanogens are a diverse group of Archaea that obligately couple energy conservation to the production of methane. Some methanogens encode alternate pathways for energy conservation, like anaerobic respiration, but the biochemical details of this process are unknown. We show that a multihemec-type cytochrome called MmcA fromMethanosarcina acetivoransis important for intracellular electron transport during methanogenesis and can also reduce extracellular electron acceptors like soluble Fe3+and anthraquinone-2,6-disulfonate. Consistent with these observations, MmcA displays reversible redox features ranging from −100 to −450 mV versus SHE. Additionally, mutants lackingmmcAhave significantly slower Fe3+reduction rates. ThemmcAlocus is prevalent in members of the OrderMethanosarcinalesand is a part of a distinct clade of multiheme cytochromes that are closely related to octaheme tetrathionate reductases. Taken together, MmcA might act as an electron conduit that can potentially support a variety of energy conservation strategies that extend beyond methanogenesis.