L22
The L22 protein is a unique ribosomal protein in that it contains a small domain containing alpha and beta units and a large beta hairpin that is almost 30 angstroms in length. Because of the large surface area associated with the hairpin, the L22 protein is one of the few proteins in the large ribosomal subunit that can interact with all six domains of the 23S rRNA. The large number of interactions has led to the conclusion that L22 is intrical in the folding mechanism of the large subunit and the ribosome as a whole. L22 is also sensitive to the antibiotic erythromycin, which can bind to the beta hairpin near the peptidyl transferase region. The structure provided above is the L22 of Thermus thermophilus, which was isolated using X-ray crystallography. (Unge et al. 1998)