Schwartz Sarah L, Rangel L Thiberio, Payette Jack G, Fournier Gregory P
Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States.
Graduate Program in Microbiology, Massachusetts Institute of Technology, Cambridge, MA, United States.
Front Microbiol. 2023 Mar 30;14:1130310. doi: 10.3389/fmicb.2023.1130310. eCollection 2023.
In addition to its role as a toxic environmental contaminant, cyanide has been hypothesized to play a key role in prebiotic chemistry and early biogeochemical evolution. While cyanide-hydrolyzing enzymes have been studied and engineered for bioremediation, the extant diversity of these enzymes remains underexplored. Additionally, the age and evolution of microbial cyanide metabolisms is poorly constrained. Here we provide comprehensive phylogenetic and molecular clock analyses of the distribution and evolution of the Class I nitrilases, thiocyanate hydrolases, and nitrile hydratases. Molecular clock analyses indicate that bacterial cyanide-reducing nitrilases were present by the Paleo- to Mesoproterozoic, and were subsequently horizontally transferred into eukaryotes. These results present a broad diversity of microbial enzymes that could be optimized for cyanide bioremediation.
除了作为一种有毒的环境污染物外，氰化物还被认为在生命起源前的化学过程和早期生物地球化学演化中发挥关键作用。虽然已对用于生物修复的氰化物水解酶进行了研究和改造，但这些酶的现有多样性仍未得到充分探索。此外，微生物氰化物代谢的年代和演化情况也知之甚少。在此，我们对I类腈水解酶、硫氰酸盐水解酶和腈水合酶的分布及演化进行了全面的系统发育和分子钟分析。分子钟分析表明，细菌中还原氰化物的腈水解酶在古元古代到中元古代就已存在，随后通过水平基因转移进入真核生物。这些结果展示了多种可用于优化氰化物生物修复的微生物酶。
