近日，美国田纳西大学教授Frank E. Löffler及其团队的研究开发出了催化氧化亚氮还原的新型细菌蛋白家族。相关论文发表在2025年8月20日出版的《自然》杂志上。

在这里，课题组研究人员报道了一个以前未被识别的蛋白质家族，它在N₂O还原中起作用，进化支III内酯酶型N₂OR (L-N2OR)，它在序列上与典型的NosZ不同，但保留了三维蛋白质结构特征。综合生理学、宏基因组学、蛋白质组学和结构模型研究表明，L-N₂ORs催化N₂O还原。L-N2OR基因存在于几个门中，主要存在于地理分布广泛的未培养类群中。他们的发现扩大了已知的N₂O多样性，并暗示了以前未被识别的N₂O消耗分类群（例如，亚硝基棘虫）。N₂OR多样性的扩大和一种新型N2O还原催化剂的鉴定促进了对N₂O汇的理解，对温室气体排放和气候变化建模具有重要意义，并扩大了旨在抑制N₂O排放的创新生物技术的机会。

据介绍，导致全球变暖和气候变化的一氧化二氮（N₂O）在地球大气中的浓度达到了前所未有的水平。目前N₂O的消耗超过了N₂O的吸收，强调需要全面了解消耗N₂O的过程。表达N₂O还原酶（N₂OR）的微生物将N₂O转化为气候变化中性的二氮（N₂）。已知的N₂OR属于典型的I和II分支NosZ还原酶，被认为是N₂O还原的关键酶。

附：英文原文

Title: A novel bacterial protein family that catalyses nitrous oxide reduction

Author: He, Guang, Wang, Weijiao, Chen, Gao, Xie, Yongchao, Parks, Jerry M., Davin, Megan E., Hettich, Robert L., Konstantinidis, Konstantinos T., Lffler, Frank E.

Issue&Volume: 2025-08-20

Abstract: Nitrous oxide (N2O), a driver of global warming and climate change, has reached unprecedented concentrations in Earth’s atmosphere1. Current N2O sources outpace N2O sinks, emphasizing the need for comprehensive understanding of processes that consume N2O. Microbes that express the enzyme N2O reductase (N2OR) convert N2O to climate change-neutral dinitrogen (N2). Known N2ORs belong to the canonical clade I and clade II NosZ reductases and are considered key enzymes for N2O reduction2,3,4. Here we report a previously unrecognized protein family with a role in N2O reduction, clade III lactonase-type N2OR (L-N2OR), which diverges in sequence from canonical NosZ but conserves three-dimensional protein structural features. Integrated physiological, metagenomic, proteomic and structural modelling studies demonstrate that L-N2ORs catalyse N2O reduction. L-N2OR genes occur in several phyla, predominantly in uncultured taxa with broad geographic distribution. Our findings expand the known diversity of N2ORs and implicate previously unrecognized taxa (for example, Nitrospinota) in N2O consumption. The expansion of N2OR diversity and the identification of a novel type of catalyst for N2O reduction advances the understanding of N2O sinks, has implications for greenhouse gas emission and climate change modelling, and expands opportunities for innovative biotechnologies aimed at curbing N2O emissions5,6.

DOI: 10.1038/s41586-025-09401-4

Source: https://www.nature.com/articles/s41586-025-09401-4