The genetic code is traditionally represented as a RNA codon table due to the biochemical nature of the protein translation process. RNA, however, substitutes uracil(U) for thymine(T) as one of its nucleotides, which is one of the main differences between RNA and DNA. However, with the rise of computational biology and genomics, proteins have become increasingly studied at a genomic level. As a result, the practice of representing the genetic code as a DNA codon table has become more popular. The DNA codons in such tables occur on the sense DNA strand and are arranged at a 5' → 3' directionality.
A The codon ATG both codes for methionine and serves as an initiation site: the first ATG in a DNA's coding region is where translation into protein begins.[1]
A Mapping of Amino Acids and Stop Signals to DNA Codons
^Nakamoto T (2009). "Evolution and the universality of the mechanism of initiation of protein synthesis". Gene. 432 (1–2): 1–6. doi:10.1016/j.gene.2008.11.001. PMID19056476. {{cite journal}}: Unknown parameter |month= ignored (help)