Binds 23S rRNA. It is not essential for growth. One of the proteins that surrounds the polypeptide exit tunnel on the outside of the subunit. Contacts trigger factor (PubMed:12226666). Part of the 50s ribosomal subunit (PubMed:1092361, PubMed:10094780, PubMed:12809609, PubMed:16272117, PubMed:21499241, PubMed:25310980, PubMed:24844575, PubMed:27934701, PubMed:27906160, PubMed:27906161). Contacts protein L23 (PubMed:2665813), trigger factor (PubMed:12226666) and protein nascent chains (PubMed:12756233). Might also contact SecE and probably does contact SecG when the SecYEG translocation complex is docked with the ribosome (PubMed:16292303). Cells missing both S17 and L29 grow very slowly and have a rather unstable temperature-sensitive phenotype. Belongs to the universal ribosomal protein uL29 family. Exchange of two tryptic peptides.