Translation Initiation in Prokaryotes

Link for Video of tRNA Charging : • tRNA Charging or Amino...
Initiation of translation in bacteria involves the assembly of the components of the translation system, which are: the two ribosomal subunits (50S and 30S subunits); the mature mRNA to be translated; the tRNA charged with N-formylmethionine (the first amino acid in the nascent peptide); guanosine triphosphate (GTP) as a source of energy, and the three prokaryotic initiation factors IF1, IF2, and IF3, which help the assembly of the initiation complex. Variations in the mechanism can be anticipated.
The ribosome has three active sites: the A site, the P site, and the E site. The A site is the point of entry for the aminoacyl tRNA (except for the first aminoacyl tRNA, which enters at the P site). The P site is where the peptidyl tRNA is formed in the ribosome. And the E site which is the exit site of the now uncharged tRNA after it gives its amino acid to the growing peptide chain.
The selection of an initiation site (usually an AUG codon) depends on the interaction between the 30S subunit and the mRNA template. The 30S subunit binds to the mRNA template at a purine-rich region (the Shine-Dalgarno sequence) upstream of the AUG initiation codon. The Shine-Dalgarno sequence is complementary to a pyrimidine rich region on the 16S rRNA component of the 30S subunit. This sequence has been evolutionarily conserved and plays a major role in the microbial world we know today. During the formation of the initiation complex, these complementary nucleotide sequences pair to form a double stranded RNA structure that binds the mRNA to the ribosome in such a way that the initiation codon is placed at the P site.

[@Dustin_-]

I have watched a few different videos on Prok translation initiation, and this one is the best explanation yet. Thank you

[@hussainbiology]

Thanks for appreciation.... Glad it helps

[@inamkakar1289]

Nice video

[@chan3858]

Thank you for uploading this video !!! Made it much more easier to understand!

[@hussainbiology]

thanks for appreciation.. Glad to know that it helps ✌️

[@srijalshukla7814]

Your work is amazing...i daily learn from your videos , it truly reflects your hardwork......Thank you so much Sir for this amazing explanation 🙏🙂

[@ashritpattanayakfan]

Thank you so much sir. Your explanations are awesome.

[@yamaziarmal4518]

May God bless you brother these videos are better than the professors at my university

[@anshikarohilla442]

Great job sir! Thank you so much fot these. You saved my life.

[@hussainbiology]

thanks for appreciation.
Glad to know that it helps ✌️

[@thienanphamphan1931]

thank you for this excellent video

[@selmadajani7246]

this is so beyond helpful. thank you so much

[@hussainbiology]

thanks for appreciation..Glad it helps

[@lujainalherz1817]

great visuals! very clear thank you.

[@hussainbiology]

thanks for appreciation..Glad it helps ✌️

[@jyotsnamayeepradhan2474]

Wow sir I am preparing for govt college lectureship,till this date i didn't understand the whole mechanism,but by ur visuals now i clearly understand all the things,thank u so much

[@hussainbiology]

All the best

[@Maurya_d59]

You're Amazing Brother ❤❤

[@Salonisharma1204]

Sir if you were not there...then I will fail definitely 🥺🥺thank a lot.....you r best ❤️ teacher ever ✨🙏🎇

[@hussainbiology]

thanks Saloni for appreciation.. Glad it helps....,✌️

[@hitangshubarman6635]

Thank you sir you have clear my confession of aminoacyl tRNA👍🏻👍🏻

[@hussainbiology]

thanks for appreciation..Glad to know that it helps ✌️

[@ThinkTangle]

Nice effort !!!

[@SanaKhan-hg4gd]

It's just amazing

[@baharetezad424]

Your videos are awsomeeee

[@hussainbiology]

thanks for appreciation

[@ammarahchaudhary2820]

Excellent video keep it up.

[@hussainbiology]

thanks Ammarah for appreciation.. Glad to know that it helps ✌️

[@anchithasanukumar3736]

Thank u sooo much....... ❣️❤️❤️❤️❤️❤️❤️❤️❤️

[@YUVATHEESWARANR]

Your videos are very clear explanation. It very useful for me
Plz u can uplode galactose metabolism in yeast
And gene organization and regulation in mitochondriaa, chloroplast

[@zinsinag7497]

Very helpful
Thank u for this

[@hussainbiology]

Thanks for appreciation..Glad it helps ✌️

[@siddhi.d5364]

Best!

[@ammaramehak9473]

thanx sir for uploadind this video , plz upload next video as early as possible .
keep it up ossum video.

[@hussainbiology]

Next video coming on Monday or Tuesday...

[@ayeshashaikh983]

Pls include video on development biology

[@biology_mcqs3037]

Keep going brother..... Soon we will be 100k

[@hussainbiology]

thanks dear....100k is still way ahead but we will hit it sooner or later

[@KrishnaKumar-ql1lv]

Thanks sir

[@ammarahmehak9986]

nice explanations keep itup.

[@hussainbiology]

thanks Ammarah ....Keep sharing and supporting ✌️

[@bommaganishyam671]

Nice sir👍

[@ammaramehak9473]

ALLAH bless you alot , be happy, keep it up sir plzzzzzzzzzzzzzzzzzzzz told about different complexes form in translation e.g pre initiation complex etc plzzzzzzz explain also ..

[@hussainbiology]

Thanks for appreciation..Glad to know that it helps ✌️

[@sreeram6416]

Next video of cell aggregation and differentiation in dictyostelium

[@SanaKhan-hg4gd]

Thank u I need it

[@hussainbiology]

thanks for appreciation... Glad it helps

[@debaswapnaray3295]

Sir plz upload d next video as fast as plz i'm waiting...

[@hussainbiology]

Coming Monday or Tuesday....

[@avavsagvs6246]

Nice

[@hussainbiology]

thanks

[@prabhudasnair7914]

were does e p a site resides
Whether in large or small subunit

[@hussainbiology]

Actually these are imaginary sites....
These are sites where amino acids enter , make bond and leave...
To be specific we can say these sites are mostly towards small subunit since mRNA is there waiting for amino acids to get Translation done

[@prabhudasnair7914]

@@hussainbiology Thanks Sir

[@emmanuelenimel5484]

It is too fast to grasp them I wanted a slower version of this

[@mehwishbatool6681]

One question
Why does1st start codon in prokaryotes code for fmet instead of methionine?? What if it initially code for methionine???

[@hussainbiology]

It is still ambiguous why it is so ..
One possibility is to act as a degradation signal. The Formyl-methionine acts as fMet/N-degrons thereby acting as a signal for degradation.
Moreover another function of fMet/N-degrons is the control of protein quality. In bacteria, the rate of polypeptide chain elongation is nearly an order of magnitude higher than in eukaryotes. We suggest that the faster emergence of nascent proteins from bacterial ribosomes is one mechanistic and evolutionary reason for the pretranslational design of bacterial fMet/N degrons, in contrast to the cotranslational design of analogous Ac/N degrons in eukaryotes.
References : NCBI and Sciencedirect

[@mehwishbatool6681]

@@hussainbiology ok thanks a lot

[@hussainbiology]

Wlcm✌️

[@jashmitudu]

sir which book you refer ...?

[@hussainbiology]

Cell Biology Alberts..
and Cell Biology Lodish

[@tanu6464]

😊😊😊😊

[@Sumitjais-uc1kg]

Actually large subunit has these 3 sites A P and E

[@hussainbiology]

Any References ??? these are all imaginary sites

[@Sumitjais-uc1kg]

@@hussainbiology yes I had studied this in 12th in my Allen module

[@ammaramehak9473]

sir plzzzzzzzzzzzz upload upcomming videos plzzzzzzzzzzzzzzzzzzzzzzzzz

[@hussainbiology]

InshaAllah very soon

[@kamemicrobiologist3620]

Waiting 👍😒😒😒

[@hussainbiology]

Wait is over

[@sandhyaindori6401]

Sir 50s and 30s makes 80s complex then y we called 70s ????

[@anandruban8348]

No its not like sum of those 50S and 30S, It is named due to the Sedimentation Co-efficient, Which is also known as Swedberg Unit and Kindly refer Density Gradient Centrifugation.

[@sandhyaindori6401]

@@anandruban8348 thank you sir

[@mohdzamaansari8267]

what's wrong wd this video??

[@hussainbiology]

Can i help ???

[@mohdzamaansari8267]

@@hussainbiology no .. now its ok... it was not playing.. bt now its ok

[@hussainbiology]

@@mohdzamaansari8267 thanks ,✌️