Shine-Dalgarno sequence

from Wikipedia, the free encyclopedia

The Shine-Dalgarno sequence is a sequence of the mRNA in prokaryotes that is recognized by the ribosomes as part of the ribosomal binding site (RBS) and thus marks the starting point of translation . In 1975 J. Shine and L. Dalgarno discovered the base pairing between mRNA and 16S rRNA in prokaryotes.

The sequence section on the mRNA which is complementary to the 16S rRNA is referred to as Shine-Dalgarno sequence 5 '… AGGAGGU… 3' . The sequence that is complementary to the Shine-Dalgarno sequence on the 16S rRNA is sometimes referred to as the anti-Shine-Dalgarno sequence. Using RNA-protein crosslinking experiments, the proteins S1 and S21 were determined to be those which interact with the 3 'end of the 16S rRNA and are involved in the initiation of translation.

In front of the translation start point ( start codon ), the mRNA has a so-called leader sequence , also known as the 5 'non-coding region (5' UTR for 5 'untranslated region ). Contrary to earlier assumptions, this has a crucial function for translation: the section that is 4-14 nucleotides in front of the start codon pairs with complementary sequences at the 3 'end of the 16S rRNA and thus enables the 30S subunit to bind of the ribosome.

The length of the complementary segment and its distance from the start codon determine the stability of the initiation complex .

In eukaryotes, the Kozak sequence takes over the function of the Shine-Dalgarno sequence.

Individual evidence

  1. ↑ Shine, J. & Dalgarno, L. (1974): The 3'-terminal sequence of Escherichia coli 16S ribosomal RNA: complementarity to nonsense triplets and ribosome binding sites. In: Proc. Natl. Acad. Sci. USA Vol. 71, pp. 1342-1346. PMID 4598299 , PMC 388224 (free full text).
  2. ↑ AP Czernilofsky et al., FEBS Lett ., Vol 58, pp. 281-284, 1975.

literature

Web links