Molecular basis of N(2) fixation in a hyperthermophilic archaeon.

Hyperthermophilic archaeal nitrogenase from Methanocaldococcus infernus exhibits the highest known activity and thermostability, with a melting temperature near water's boiling point.

• Why it matters: Understanding diverse nitrogenases is essential for advancing sustainable ammonia production and revealing the mechanisms of atmospheric N2 fixation, especially in extreme environments.
• What they did: Researchers isolated and characterized the enzyme at 92°C, determined near-atomic resolution crystal structures, and identified structural features that confer thermostability and mechanistic insights.
• The result: The enzyme's stability and structural simplicity enable new understanding of nitrogen fixation, suggesting potential biotechnological applications and evolutionary links among nitrogenase isoforms.