How does the eukaryotic initiation complex locate the correct start codon?
◦ The true start codon is the first ATG encountered downstream of the Shine-Dalgarno sequence.
◦ The initiation complex moves the small ribosomal subunit through the 5′ UTR, scanning for the start AUG.
◦ The pre-initiation complex moves the ribosome through the 3′ UTR, scanning for the Kozak sequence.
◦ The correct start codon is the first ATG encountered downstream of the Kozak sequence.
◦ The correct start codon is the formyl-ATG, which will encode for fMet in the protein.