Lab Evolved Proteins (image) Arizona State University Caption The 3-D structure (ribbon diagram) of protein DX (gray) superimposed with the parent sequence, protein 18-19 (gold). The zinc metal ion is shown in orange and the ATP ligand is colored by atom type. Credit John Chaput, Biodesign Institute at Arizona State University Usage Restrictions None 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.