Curling protein structures image (IMAGE) University of Göttingen Caption Protein structure with the newly identified switch between a cysteine and lysine residue showing its structure and electron density. This discovery has wide-reaching implications for understanding and treating diseases. Credit K Tittmann Usage Restrictions None 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.