The shine dalgarno sequence is a ribosomal site in the prokaryotic bacterial mRNA which helps in protein synthesis by aligning the ribosome with the start codon. It's significance deals with it's effect and importance during the translation process within an mRNA.

1. SIGNIFICANCE OF SHINE
DALGARNO SEQUENCE.
Submitted By:
Prajakta Panda
190704180001
B.Sc Biochemistry (4th sem)
CUTM
BBSR Campus

2. CONTENTS
• OVERVIEW ON TRANSLATION AND IT’S PROCESSES
• STEPS INCLUDED IN TRANSLATION
• INTRODUCTION TO SD SEQUENCE
• WHERE IT IS FOUND?
• DELETION OF SD SEQUENCE
• IT’S IMPORTANCE
• CONCLUSION

3. TRANSLATION AND ITS PROCESSES
• Translation is the process by which a protein is synthesized from the information
contained in a molecule of messenger RNA (mRNA).
• During translation mRNA is read using the genetic code. The genetic code is a set of
three letter combinations of nucleotides called codons.
• Codons are of different types. A start codon is used to mark the sites at which
translation into protein sequence begins. The another stop codon is used to mark
the site at which translation ends.
• Translation occurs at ribosome. The ribosome contains a large subunit (50S), a small
subunit (30S), an entrance for tRNA molecules (A site), a site of elongation (P site)
and an exit site for tRNAs (E site).
• Translation occurs in 3 stages: Initiation, Elongation, and Termination.

4. STEPS INCLUDED IN TRANSLATION
mRNA binds to the small subunit of
the ribosome.
tRNA with anticodon complementary
to the first codon to be translated on
the mRNA binds to the ribosome.
A second tRNA with an anticodon
complementary to the second codon
on the mRNA then binds to the
ribosome.
Ribosome transfers the amino acid on
the second tRNA making a new
peptide makes a new dipeptide
because the second tRNA is now
carrying a chain of two amino acids.
Ribosome moves along the mRNA so
the first tRNA is released and the
second tRNA becomes the first.
Another tRNA binds with an
anticodon complementary to the next
codon on the mRNA.
Ribosome transfers the chain of amino
acids carried by the first tRNA to the
amino acid on the second tRNA
making a new peptide bond.

5. DELETION OF SD SEQUENCE
• In bacteria, the small ribosomal subunit
binds to the Shine-Dalgarno sequence
to initiate translation. If the Shine-
Dalgarno sequence is deleted, then
translation initiation cannot take place,
preventing protein synthesis.

6. Introduction to SD sequence
• Shine Dalgarno sequence is a sequence of 5 to 9 (typically 7) nucleotide preceding
the start codon in prokaryotic mRNA that is recognized by the ribosome as the
correct site for binding the mRNA molecule prior to start of translation.
• The sequence (AGGAGGU) binds a complementary sequence on the 16S ribosomal
subunit, helping to form a stable complex between the ribosome and mRNA.
• The role of this sequence was first proposed by John Shine and Lynn Dalgarno.

7. WHERE IT IS FOUND?
It is found near
the start codon
in prokaryotes.

8. IT’S IMPORTANCE
• It helps to initiate translation by binding the mRNA to the ribosome near the first
AUG.
• It enables the initiation of protein synthesis by aligning the ribosome with start
codon.
• It base pairs with the 16S rRNA. It can be on the end or it can be in the middle of an
RNA.

9. Conclusion.
The function of Shine-Dalgarno
sequence is the ribosome
binding site on mRNA molecule.

10. Reference
Encyclopedia
Slide share
Quizlet
Science direct

11. THANK YOU!