The G-to-R substitution at the VL-CL linker region is being degenerately encoded by different nucleotide sequences. One of the most frequent VL CDR3 of subsets 2 and 169 is depicted. The amino acids of the VL CDR3 region are enclosed in boxes of different shades of gray. The R residue at the VL-CL linker region is in a black box and can be encoded by 6 different nucleotide triplets. The prevailing triplet is set in bold. CL, constant light; FR, framework region.