AbyU Enzyme (IMAGE) University of Bristol Caption The antibiotic abyssomycin formed in the cavity of AbyU, a natural Diels-Alder enzyme with a simple beta-barrel fold. The orange spheres indicate the atoms involved in the newly formed bonds. Credit P. Race Usage Restrictions Only to be used to illustrate the accompanying story. License Licensed 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.