Aminoacyl-tRNA synthetase: A ‘semiotic enzyme’

The genetic code is the set of rules by which nucleotide sequences correspond to amino acids. These rules are enforced by aminoacyl-tRNA synthetases (aaRSs): enzymes that ligate amino acids to tRNA molecules. Here it is argued this reaction suggests the genetic code may be understood as a 'code process'. Contrary to the prevailing adaptor model of the genetic code based on tRNAs, the semiotic model recognises a 'genetic code process' catalysed by aaRSs.