Binds the 23S rRNA. One of the proteins that surrounds the polypeptide exit tunnel on the outside of the subunit. Part of the 50S ribosomal subunit. Contacts protein L23 and trigger factor when it is complexed with the ribosome (PubMed:16091460 and PubMed:16271892). Belongs to the universal ribosomal protein uL29 family.