Forms part of the ribosomal stalk which helps the ribosome interact with GTP-bound translation factors. Is thus essential for accurate translation. Homodimer. Part of the ribosomal stalk of the 50S ribosomal subunit. Forms a multimeric L10(L12)X complex, where L10 forms an elongated spine to which 2 to 4 L12 dimers bind in a sequential fashion. Binds GTP-bound translation factors. Detected in both the small cell variant (SCV) and in the large cell variant (LCV) stage (at protein level). LCVs are more metabolically active than SCVs. Belongs to the bacterial ribosomal protein bL12 family.