Yang Sui Nin Nicholas, Kertesz Michael A, Coleman Nicholas V
School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia.
Australian Genome Foundry and ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales, Australia.
Environ Microbiol. 2025 Feb;27(2):e70050. doi: 10.1111/1462-2920.70050.
Monooxygenase (MO) enzymes are responsible for the oxidation of hydrocarbons and other compounds in the carbon and nitrogen cycles, are important for the biodegradation of pollutants and can act as biocatalysts for chemical manufacture. The soluble di-iron monooxygenases (SDIMOs) are of interest due to their broad substrate range, high enantioselectivity and ability to oxidise inert substrates such as methane. Here, we re-examine the phylogeny and functions of these enzymes, using recent advances in the field and expansions in sequence diversity in databases to highlight relationships between SDIMOs and revisit their classification. We discuss the impact of horizontal gene transfer on SDIMO phylogeny, the potential of SDIMOs for the biodegradation of pollutants and the importance of heterologous expression as a tool for understanding SDIMO functions and enabling their use as biocatalysts. Our analysis highlights current knowledge gaps, most notably, the unknown substrate ranges and physiological roles of enzymes that have so far only been detected via genome or metagenome sequencing. Enhanced understanding of the diversity and functions of the SDIMO enzymes will enable better prediction and management of biogeochemical processes and also enable new applications of these enzymes for biocatalysis and bioremediation.
单加氧酶（MO）在碳循环和氮循环中负责碳氢化合物及其他化合物的氧化，对污染物的生物降解至关重要，还可作为化学制造的生物催化剂。可溶性二铁单加氧酶（SDIMOs）因其广泛的底物范围、高对映选择性以及氧化甲烷等惰性底物的能力而备受关注。在此，我们利用该领域的最新进展以及数据库中序列多样性的扩展，重新审视这些酶的系统发育和功能，以突出SDIMOs之间的关系并重新审视它们的分类。我们讨论了水平基因转移对SDIMO系统发育的影响、SDIMOs在污染物生物降解方面的潜力以及异源表达作为理解SDIMO功能并使其用作生物催化剂的工具的重要性。我们的分析突出了当前的知识空白，最显著的是，那些迄今仅通过基因组或宏基因组测序检测到的酶，其未知的底物范围和生理作用。对SDIMO酶的多样性和功能的深入理解将有助于更好地预测和管理生物地球化学过程，还能使这些酶在生物催化和生物修复方面有新的应用。
