Based on a binary representation of purines and pyrimidines, our new classification scheme of the genetic code can easily highlight codon symmetries and regularities as well as patterns of amino acid assignment. One example is a “codon – reverse codon” pattern. It is well known that there is no tRNA with an anticodon for any of the STOP codons; but interestingly there is also no tRNA containing reverse STOP anticodons in genomes. We observed that the patterm of “codon – reverse codon” is correlated to this interesting aspect and may provide some hints about the early evolution of the genetic code.
To detect traces of possible binary coding in genomes we developed the genome browser DiProGB, which enables to encode any genome or genetic sequences by different binary coding schemes as well as by physicochemical or geometrical dinucleotide properties.