Life on Earth has existed for nearly 4 billion years, and for most of that time, it was microbial (1). The diverse world we see around us today owes its entire existence to a few foundational events c...

YouTube video by The Well

YouTube video by The Badger Herald

Life on Earth has existed for nearly 4 billion years, and for most of that time, it was microbial (1). The diverse world we see around us today owes its entire existence to a few foundational events c...

This Perspective discusses virus-encoded auxiliary metabolic genes and provides a framework for the biological interpretation of these genes.

Life on Earth has been shaped by transformative microbial innovations and singularities that redefined planetary systems

Previously, we identified the only dinitrogen reduction mechanism known to date as an ancient feature conserved from nitrogenase ancestors, which we directly tested by resurrecting and integrating synthetic ancestral nitrogenases into the genome of Azotobacter vinelandii (Garcia et al., 2023), a genetically tractable, nitrogen-fixing model bacterium. Here, we extend this paleomolecular approach to investigate the structural evolution of nitrogenase over billions of years of evolution by combining phylogenetics, ancestral sequence reconstruction, protein crystallography, and deep-learning based predictions. This study reveals that nitrogenase, while maintaining a conserved multimeric core, evolved novel modular features aligned with major environmental transitions, suggesting that subtle distal changes and transient regulatory adaptations were key to its long-term persistence and to shaping protein evolution over geologic time. The framework established here provides a foundation for identifying structural constraints that governed ancient proteins and for situating their sequences and structures within phylogenetic and environmental contexts across time.