Lab Evolved Proteins (image) Arizona State University Share Print E-Mail 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 Share Print E-Mail 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.