Oxygen-protected FeSII-nitrogenase complex cryoEM structure (VIDEO) University of California - San Diego This video is under embargo. Please login to access this video. Caption Overview of the O₂-protected FeSII-nitrogenase complex cryoEM structure and proposed mechanism for the formation of the complex in the presence of O₂ and its subsequent dissociation once O₂ is removed. Credit Brian Cook and Sarah Narehood / UC San Diego Usage Restrictions editorial use only License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.