Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years.

ABSTRACT: Nitrogen isotope fractionation (ε¹⁵N) in sedimentary rocks has provided evidence for biological nitrogen fixation, and thus primary productivity, on the early Earth. However, the extent to which molecular evolution has influenced the isotopic signatures of nitrogenase, the enzyme that catalyzes the conversion of atmospheric nitrogen (N₂) to bioavailable ammonia, remains unresolved. Here, we reconstruct and experimentally characterize a library of synthetic ancestral nitrogenase genes, spanning over 2 billion years of evolutionary history. We assess the resulting ε¹⁵N values under controlled laboratory conditions. All engineered strains exhibit ε¹⁵N values within a narrow range comparable to that of modern microbes, suggesting that molybdenum (Mo)-dependent nitrogenase

SUBMITTER: Rucker HR 

PROVIDER: S-EPMC12828030 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature