Forms part of the ribosomal stalk which helps the ribosome interact with GTP-bound translation factors. Part of the ribosomal stalk of the 50S ribosomal subunit (PubMed:15923259). Interacts with L10 and the large rRNA to form the base of the stalk. L10 forms an elongated spine to which 2 L12 dimers bind in a sequential fashion forming a pentameric L10(L12)2(L12)2 complex (PubMed:15923259). Belongs to the universal ribosomal protein uL11 family.