Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA.
Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA.
Microbiol Spectr. 2022 Aug 31;10(4):e0189322. doi: 10.1128/spectrum.01893-22. Epub 2022 Jul 25.
Iron sulfur (Fe-S) proteins are essential and ubiquitous across all domains of life, yet the mechanisms underpinning assimilation of iron (Fe) and sulfur (S) and biogenesis of Fe-S clusters are poorly understood. This is particularly true for anaerobic methanogenic archaea, which are known to employ more Fe-S proteins than other prokaryotes. Here, we utilized a deep proteomics analysis of Methanococcus voltae A3 cultured in the presence of either synthetic pyrite (FeS) or aqueous forms of ferrous iron and sulfide to elucidate physiological responses to growth on mineral or nonmineral sources of Fe and S. The liquid chromatography-mass spectrometry (LCMS) shotgun proteomics analysis included 77% of the predicted proteome. Through a comparative analysis of intra- and extracellular proteomes, candidate proteins associated with FeS reductive dissolution, Fe and S acquisition, and the subsequent transport, trafficking, and storage of Fe and S were identified. The proteomic response shows a large and balanced change, suggesting that M. voltae makes physiological adjustments involving a range of biochemical processes based on the available nutrient source. Among the proteins differentially regulated were members of core methanogenesis, oxidoreductases, membrane proteins putatively involved in transport, Fe-S binding ferredoxin and radical S-adenosylmethionine proteins, ribosomal proteins, and intracellular proteins involved in Fe-S cluster assembly and storage. This work improves our understanding of ancient biogeochemical processes and can support efforts in biomining of minerals. Clusters of iron and sulfur are key components of the active sites of enzymes that facilitate microbial conversion of light or electrical energy into chemical bonds. The proteins responsible for transporting iron and sulfur into cells and assembling these elements into metal clusters are not well understood. Using a microorganism that has an unusually high demand for iron and sulfur, we conducted a global investigation of cellular proteins and how they change based on the mineral forms of iron and sulfur. Understanding this process will answer questions about life on early earth and has application in biomining and sustainable sources of energy.
铁硫（Fe-S）蛋白在所有生命领域都是必不可少且普遍存在的，但铁（Fe）和硫（S）的同化以及 Fe-S 簇的生物发生的机制仍知之甚少。对于厌氧产甲烷古菌来说尤其如此，已知它们比其他原核生物使用更多的 Fe-S 蛋白。在这里，我们利用 Methanococcus voltae A3 在含有合成黄铁矿（FeS）或亚铁和硫化物的水溶液的条件下进行的深度蛋白质组学分析，阐明了对以矿物或非矿物来源的 Fe 和 S 生长的生理反应。液相色谱-质谱（LCMS）shotgun 蛋白质组学分析包括预测蛋白质组的 77%。通过对细胞内和细胞外蛋白质组的比较分析，鉴定出与 FeS 还原溶解、Fe 和 S 摄取以及随后的 Fe 和 S 运输、转运和储存相关的候选蛋白。蛋白质组学反应显示出大量且平衡的变化，表明 M. voltae 根据可用营养源进行涉及一系列生化过程的生理调整。在差异调节的蛋白质中，有核心产甲烷作用、氧化还原酶、膜蛋白的成员，这些蛋白可能涉及运输，Fe-S 结合的铁氧还蛋白和自由基 S-腺苷甲硫氨酸蛋白，核糖体蛋白和参与 Fe-S 簇组装和储存的细胞内蛋白。这项工作提高了我们对古老生物地球化学过程的理解，并可以支持矿物生物采矿的努力。铁和硫簇是促进微生物将光能或电能转化为化学键的酶的活性位点的关键组成部分。负责将铁和硫运输到细胞内并将这些元素组装成金属簇的蛋白质尚不清楚。使用一种对铁和硫有异常高需求的微生物，我们对细胞蛋白进行了全面调查，以及它们如何根据铁和硫的矿物形式发生变化。了解这个过程将回答关于早期地球生命的问题，并在生物采矿和可持续能源方面有应用。
