The ribosomal protein L7/L12 with the substitution of Cys38 for the Val38 residue was obtained and studied to test the orientation of polypeptide chains in the N-terminal region of the dimer. The results show that the L7/L12 dimer has a parallel (head-to-head) orientation of subunits and that its first 37 N-terminal residues are sufficient for dimerization.
