Shine Dalgarno Sequence | Anti Shine Dalgarno Sequence

#drnajeeb #shinedalgarno

Shine Dalgarno Sequence | Anti Shine Dalgarno Sequence

Like this video?
Sign up now on our website at https://www.DrNajeebLectures.com to access 1000+ Exclusive videos on Basic Medical Sciences & Clinical Medicine. These are premium videos (NOT FROM YOUTUBE). All these videos come with English subtitles & download options. Sign up now! Get Lifetime Access for a one-time payment of $24 ONLY!

Sign up now on our website at https://members.drnajeeblectures.com/
---------------------------------------------------------------------------------------------------------------------------
Why sign up for premium membership? Here's why!
Membership Features for premium website members.

1. More than 1000+ Medical Lectures.
2. Basic Medical Sciences & Clinical Medicine.
3. Mobile-friendly interface with android and iOS apps.
4. English subtitles and new videos every week.
5. Download option for offline video playback.
6. Fanatic customer support and that's 24/7.
7. Fast video playback option to learn faster.
8. Trusted by over 2M+ students in 190 countries.
---------------------------------------------------------------------------------------------------------------------------
▬▬▬▬▬▬▬▬▬▬ Contents of this video ▬▬▬▬▬▬▬▬▬▬

This Short is a clip from the lecture "Prokaryotic Protein Synthesis (Translation) - Initiation & Clinical Co-Relates
Type"

To watch this complete lecture please visit our website. 👇🏻👇🏻👇🏻

www.drnajeeblectures.com

If you Sign Up Now you can get lifetime access to our premium lectures for just $45 ONLY.

So hurry up and sign up now.

The link is below. 👇🏻👇🏻👇🏻👇🏻👇🏻👇🏻👇🏻👇🏻👇🏻

https://members.drnajeeblectures.com/...

The Shine–Dalgarno (SD) sequence is a ribosomal binding site in bacterial and archaeal messenger RNA, generally located around 8 bases upstream of the start codon AUG. 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. 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 GAGG dominates in E. coli virus T4 early genes.

The Shine–Dalgarno sequence was proposed by Australian scientists John Shine and Lynn Dalgarno in 1973.

Translation initiation in prokaryotes is mainly defined, although not exclusively, by the interaction between the anti-Shine-Dalgarno sequence (antiSD), located at the 3’-terminus of the 16S ribosomal RNA, and a complementary sequence, the ribosome binding site, or Shine-Dalgarno (SD), located upstream of the start codon in prokaryotic mRNAs. The antiSD has a conserved 5’-CCUCC-3’ core, but inter-species variations have been found regarding the participation of flanking bases in binding. These variations have been described for certain bacteria and, to a lesser extent, for some archaea. To further analyze these variations, we conducted binding-energy prediction analyses on over 6,400 genomic sequences from both domains. We identified 15 groups of antiSD variants that could be associated with the organisms’ phylogenetic origin. Additionally, our findings revealed that certain organisms exhibit variations in the core itself. Importantly, an unaltered core is not necessarily required for the interaction between the 3’-terminus of the rRNA and the region preceding the AUG of the mRNA. In our study, we classified organisms into four distinct categories: i) those possessing a conserved core and demonstrating binding; ii) those with a conserved core but lacking evidence of binding; iii) those exhibiting binding in the absence of a conserved core; and iv) those lacking both a conserved core and evidence of binding. Our results demonstrate the flexibility of organisms in evolving different sequences involved in translation initiation beyond the traditional Shine-Dalgarno sequence. These findings are discussed in terms of the evolution of translation initiation in prokaryotic organisms.