Proteins Evolution (image) Max-Planck-Gesellschaft Share Print E-Mail Caption At first glance, proteins that fold into a barrel-like shape (left) and proteins that fold into a sandwich-like shape (right) appear completely different. However, analyses of their amino acid sequences as well as a recently identified intermediate form (centre) have revealed similarities that suggest a common evolutionary origin. Credit MPI for Developmental Biology /B. Höcker 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.