Quantification analysis of translation initiation signal in vertebrate mRNAs: Effect of nucleotides at positions +4 ∼ +6 upon efficiency of translation initiation

Concerning initiation mRNAs, a (GCC)GCC(A proposed, sequences the translation signal in vertebrate consensus sequence, or OCCATGG, has been but actual initiation differ from it in a greater or lesser degree. Kozak monitored selection by ribosomes of the first versus second ATG codons as a function of mutations introduced at positions +4, +5, and +6 of the first ATG codon. Codons possessing G at +4 strongly enhanced selection of the first ATG codon. However, ATG codon recognition was unaffected by most mutations in positions +5 and +6. These data were well understood by our quantification analysis.