The Role of the Tunnel (IMAGE) University of Freiburg Caption The protein-sorting complex SRP scans the ribosome protein tunnel where proteins are being synthesized. When it recognizes a protein of the right kind, SRP positions its binding pocket at the end of the tunnel, where it forms a stable complex with the protein and transports it to the target site in the membrane. Credit Graphic: AG Koch Usage Restrictions The image may only be used with appropriate caption or credit. 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.