This is one of the proteins that binds to the 5S RNA in the ribosome where it forms part of the central protuberance. Binds to the 5S rRNA independently of L5 and L18. Not required for binding of the 5S rRNA/L5/L18 subcomplex to 23S rRNA. Part of the 50S ribosomal subunit (PubMed:1093874, PubMed:1100506, Ref.4, PubMed:10094780, PubMed:10756104, PubMed:12809609, PubMed:16272117, PubMed:25310980, PubMed:24844575, PubMed:27934701, PubMed:27906160, PubMed:27906161); part of the 5S rRNA/L5/L18/L25 subcomplex (PubMed:354687, PubMed:8925931). Contacts the 5S rRNA (PubMed:3298242, PubMed:10562563, PubMed:10696113). Belongs to the bacterial ribosomal protein bL25 family.