Once recruited, tRNA may add amino acids in sequence as dictated by the codons, moving downstream from the translational start site.
[1] Many studies have confirmed that base pairing between the Shine–Dalgarno sequence in mRNA and the 3' end of 16S rRNA is of prime importance for initiation of translation by bacterial ribosomes.
[citation needed] In F1 phage, a class of viruses that infect bacteria, the sequence coding for the first few amino acids often contains termination triplets in the two unused reading frames.
[further explanation needed][10] In a commentary on this paper, it was noted that complementary base pairing with the 3'-terminus of 16S rRNA might serve to abort peptide bond formation after out-of-phase initiation.
This change is due to a reduced or increased mRNA-ribosome pairing efficiency, as evidenced by the fact that compensatory mutations in the 3'-terminal 16S rRNA sequence can restore translation.