Shine-Dalgarno sequence

Examples of Shine-Dalgarno sequence in the following topics:

• Attenuation

  • The attenuator is transcribed from the appropriate DNA sequence and its effects are dependent on the metabolic environment.
  • In times of need, the attenuator within the mRNA sequence will be bypassed by the ribosome and proper translation will occur.
  • Translation-attenuation is characterized by the sequestration of the Shine-Dalgarno sequence.
  • The Shine-Dalgarno sequence is a bacterial specific sequence that indicates the site for ribosomal binding to allow for proper translation to occur.
  • However, in translation-attenuation, the attenuation mechanism results in the Shine-Dalgarno sequence forming as a hairpin-loop structure.

• Scarlet Fever

  • The speA gene was cloned and sequenced in 1986.
  • Removal of the signal sequence gives a predicted molecular weight of 25.787 (kDa) for the secreted protein.
  • Both a promoter and a ribosome-binding site (Shine-Dalgarno sequence) are present upstream of the gene.

• Regulation by Biosynthetic Enzymes

  • There are now many equivalent examples where the translation, not transcription, is terminated by sequestering the Shine-Dalgarno sequence (ribosomal binding site) in a hairpin-loop structure.
  • Attenuator is a nucleotide sequence in DNA that can lead to premature termination of transcription.
  • (This differs from eukaryotic cells, where RNA must exit the nucleus before translation starts. ) The attenuator sequence, which is located between the mRNA leader sequence (5' UTR) and trp operon gene sequence, contains four domains, where domain 3 can pair with domain 2 or domain 4.
  • The attenuator sequence at domain 1 contains instruction for peptide synthesis that requires tryptophans.
  • The attenuator sequence has its codons translated into a leader peptide, but is not part of the trp operon gene sequence.