This protein binds specifically to 23S rRNA. The globular domain of the protein is located near the polypeptide exit tunnel on the outside of the subunit, while an extended beta-hairpin is found that lines the wall of the exit tunnel in the center of the 70S ribosome. Part of the 50S ribosomal subunit. Belongs to the universal ribosomal protein uL22 family. Young tissue from this organism is photosynthetic and contains some thylakoids, although the photosynthetic activity does not exceed the light compensation point.