Ribosomal protein L22/L17e. L22 (L17 in eukaryotes) is a core protein of the large ribosomal subunit. It is the only ribosomal protein that interacts with all six domains of 23S rRNA, and is one of the proteins important for directing the proper folding and stabilizing the conformation of 23S rRNA. L22 is the largest protein contributor to the surface of the polypeptide exit channel, the tunnel through which the polypeptide product passes. L22 is also one of six proteins located at the putative translocon binding site on the exterior surface of the ribosome.