Bacterial estrogenesis without oxygen: Wood-Ljungdahl pathway likely contributed to the emergence of estrogens in the biosphere

• 成果类型: Article
• 署名作者: Wang, Po-Hsiang; Wu, Tien-Yu; Chen, Yi-Lung; Gicana, Ronnie G.; Lee, Tzong-Huei; Chen, Mei-Jou; Hsiao, Tsun-Hsien; Lu, Mei-Yeh Jade; Lai, Yi-Li; Wang, Tzi-Yuan; Li, Jeng-Yi; Chiang, Yin-Ru
• 署名单位: National Central University; Academia Sinica - Taiwan; National Taiwan University; National Taiwan University; National Taiwan University; National Taiwan University Hospital; National Taiwan University; National Tsing Hua University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14088
• DOI: 10.1073/pnas.2422930122
• 发表日期: 2025-03-11
• 关键词: biosynthesis; receptor; methyltransferases; androgens; EVOLUTION; enzymes; protein; GROWTH

摘要

Androgen and estrogen, key sex hormones, were long thought to be exclusively produced by vertebrates. The O2-dependent aromatase that converts androgen to estrogen (estrogenesis) has never been identified in any prokaryotes. Here, we report the finding of anaerobic estrogenesis in a Peptococcaceae bacterium (Phosphitispora sp. strain TUW77) isolated from the gut of the great blue-spotted mudskipper (Boleophthalmus pectinirostris). This strain exhibits testosterone fermentation pathways, transforming testosterone into estrogens and androstanediol under anaerobic conditions. Physiological experiments revealed that strain TUW77 grows exclusively on testosterone, utilizing the androgenic C-19 methyl group as both the carbon source and electron donor. The genomic analysis identified three copies of a polycistronic gene cluster, abeABC (anaerobic bacterial estrogenesis), encoding components of a classic cobalamin-dependent methyltransferase system. These genes, highly expressed under testosterone-fed conditions, show up to 57% protein identity to the characterized EmtAB from denitrifying Denitratisoma spp., known for methylating estrogen into androgen (the reverse reaction). Tiered transcriptomic and proteomic analyses suggest that the removed C-19 methyl group is completely oxidized to CO2 via the oxidative Wood-Ljungdahl pathway (WLP), while the reducing equivalents (NADH) fully reduce remaining testosterone to androstanediol. Consistently, the addition of anthraquinone-2,6-disulfonate, an extracellular electron acceptor, to testosterone-fed TUW77 cultures enabled complete testosterone conversion into estrogen without androstanediol accumulation (anaerobic testosterone oxidation). This finding of aromatase-independent estrogenesis in anaerobic bacteria suggests that the ancient WLP may have contributed to the emergence of estrogens in the early biosphere.