Editing Shine–Dalgarno sequence (section)

===Translation termination===
In 1973 Dalgarno and Shine proposed that in [[eukaryotes]], the 3'-end of the small 18S rRNA may play a role in the termination of protein synthesis by complementary base pairing with termination codons.<ref>{{cite journal |vauthors=Dalgarno L, Shine J | year = 1973 | title = Conserved terminal sequence in 18S rRNA may represent terminator anticodons | journal = Nature | volume = 245 | issue = 148| pages = 261–262 | doi=10.1038/newbio245261a0| pmid = 4202225 }}</ref> This came from their observation that the 3' terminal sequences of 18S rRNA from ''Drosophila melanogaster'', ''Saccharomyces cerevisiae'', and rabbit cells are identical: GAUCAUUA -3'OH.<ref>{{cite journal | author = Hunt J A | year = 1965 | title = Terminal-sequence studies of high-molecular-weight ribonucleic acid. The reaction of periodate-oxidized ribonucleosides, 5'-ribonucleotides and ribonucleic acid with isoniazid | journal = Biochemical Journal | volume = 95 | issue = 2| pages = 541–51 | doi=10.1042/bj0950541| pmid = 14340106 | pmc = 1214355 }}</ref>  The conservation of this sequence between such distantly related eukaryotes implied that this nucleotide tract played an important role in the cell.  Since this conserved sequence contained the complement of each of the three eukaryotic termination codons (UAA, UAG and UGA) it was proposed to have a role in the termination of protein synthesis in eukaryotes.  A similar role for the 3' end of 16S rRNA in recognising termination triplets in ''E.coli ''was proposed in 1974 by Shine and Dalgarno on the basis of complementarity relationships between the 3'-terminal UUA-OH in 16S rRNA and ''E.coli'' termination codons.{{Citation needed|date=April 2016}}  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.{{Elucidate|date=April 2016}}<ref>{{cite journal |vauthors=Pieczenik G, Model P, Robertson HD | year = 1974 | title = Sequence and symmetry in ribosome binding sites of bacteriophage f1RNA | journal = Journal of Molecular Biology | volume = 90 | issue = 2| pages = 191–214| doi=10.1016/0022-2836(74)90368-4| pmid = 4375722 }}</ref> 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.<ref>{{cite journal | author = Anon  | year = 1976 | title = Signals for protein synthesis | journal = Nature | volume = 260 | issue = 5546| pages = 12–13 | doi=10.1038/260012a0| bibcode = 1976Natur.260...12A | doi-access = free }}</ref>