Figure 3From: The Proteomic Code: a molecular recognition code for proteinsOrigin of the Proteomic Code. Threonine (Thr) is coded by 4 different synonymous codons. Complementary triplets encode different amino acids in parallel (3'→5') and anti-parallel (5'→3') readings. Amino acids encoded by symmetrical codons are called "primary" and others "secondary" anti-sense amino acids (modified from [9].Back to article page