Editing Shine–Dalgarno sequence (section)

{{short description|Ribosomal binding site in prokaryotic messenger RNA}}
The '''Shine–Dalgarno''' ('''SD''') '''sequence''' is, sometimes partially, part of a [[ribosomal binding site]] in bacterial and archaeal [[messenger RNA]].<ref>{{Cite journal |last=Chen |first=Hongyun |last2=Bjerknes |first2=Matthew |last3=Kumar |first3=Ravindra |last4=Jay |first4=Ernest |date=1994 |title=Determination of the optimal aligned spacing between the Shine – Dalgarno sequence and the translation initiation codon of Escherichia coli m RNAs |url=https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/22.23.4953 |journal=Nucleic Acids Research |language=en |volume=22 |issue=23 |pages=4953–4957 |doi=10.1093/nar/22.23.4953 |issn=0305-1048 |pmc=523762 |pmid=7528374}}</ref> It is generally located around 8 bases [[Upstream and downstream (DNA)|upstream]] of the [[start codon]] AUG.<ref name=":0" /> The RNA sequence helps recruit the [[ribosome]] to the [[messenger RNA]] (mRNA) to initiate [[protein synthesis]] by aligning the ribosome with the start codon. Once recruited, [[tRNA]] may add amino acids in sequence as dictated by the codons, moving downstream from the translational start site. 

The Shine–Dalgarno sequence is common in [[bacteria]], but rarer in [[archaea]].<ref name="pmid21265752">{{cite journal |last1=Benelli |first1=D |last2=Londei |first2=P |title=Translation initiation in Archaea: conserved and domain-specific features. |journal=Biochemical Society Transactions |date=January 2011 |volume=39 |issue=1 |pages=89–93 |doi=10.1042/BST0390089 |pmid=21265752}}</ref> It is also present in some [[chloroplast]] and [[mitochondrial]] transcripts. The six-base [[consensus sequence]] is '''AGGAGG'''; in ''[[Escherichia coli]]'', for example, the sequence is AGGAGGU, while the shorter {{tt|GAGG}} dominates in [[Enterobacteria phage T4|''E. coli'' virus T4]] [[early gene]]s.<ref name=":0">{{cite journal |author=Malys N |title=Shine-Dalgarno sequence of bacteriophage T4: GAGG prevails in early genes |journal=Molecular Biology Reports |volume=39 |issue=1 |pages=33–9 |year=2012 |pmid=21533668 |doi=10.1007/s11033-011-0707-4|title-link=early gene |s2cid=17854788 }}</ref>

The Shine–Dalgarno sequence was proposed by [[Australia]]n scientists [[John Shine]] and [[Lynn Dalgarno]] in 1973.