The drug erythromycin (red) blocks the tunnel from which a newly synthesized protein emerges from the ribosome. The image is a top view of the 50S ribosomal subunit in the bacterium Deinococcus radiodurans. Ribosomal RNAs are shown in blue, and ribosomal proteins in gold.
[Dr. Joerg Harms, MPI for Molecular Genetics, Berlin, Germany.]