This observation was further supported by a multivariate study of the relationship between the genetic code and the physical-chemical properties of amino acids [77].
In arthropod mitogenomes, correlated evolution between the genetic code and the tRNASer/tRNALys has been revealed, which invokes that the arthropod species predicted to decode AGG as Ser change the typical anticodon GCU of tRNASer either to UCU or ACU, whereas the species predicted to decode AGG as Lys have the anticodon CUU of tRNALys [12].
The tradeoff is determined by the interplay between the genetic code, optimization of the codon entropy, and demands on the structure and stability of nucleic acids and proteins.
Interestingly, more concordance between the genetic code and amino acid composition was found in Eukaryota than in the other two domains.
The compatibility between the genetic code and amino acid composition of proteomes is also worthy of further study, because it may provide some clues about their co- adaptation.
Transfer RNAs (tRNAs) are members of a family of ubiquitous molecules that provide the essential link between the genetic code and amino acids.
Overall, the interplay between the genetic code, optimization of the codon entropy, and demands on the structure and stability of nucleic acids and proteins chiefly determine the tradeoff throughout the whole interval of the genomic GC values.
It is instructive to analyze the relationships between the genetic code and its fitness from a reverse perspective, i.e., to derive the best matrix of amino acid substitution costs for a given (e.g., standard) code.
4. Others [ e.g. [ 4, 32- 35]] have postulated an ancestral link between the genetic code and the operational RNA code, which occurs in the acceptor stem of contemporary tRNAs [ 4].
Though advances in genomic sequencing provided many opportunities for deciphering the link between the genetic code and its biological outcome, the derivation of meaningful information from such large datasets is, as stated earlier, still challenging.
