"asmi" wrote:
what is the role of shine dalgarno sequence in prokaryotes /5' MeG cap in eukaryotes ?
"SHINE DALGARNO sequence (only in prokaryotes) is found in the untranslated region (UTR), upstream of initial codon(AUG) of @ gene transcribed."(KaplanBiochem)
 In short-it's an untranslated gene found in the mRNA spcifically just before the start point of the coding region.
My mnemonic for that is: the sun SHINES BEFORE prokaryotes START
:wink:
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On the other hand, 5' cap due to a 7-MethylGUANOSINE (only in EUK) is a post-translational modification of mRNA. its purpose it for ribosome binding and protection for mRNA degradation.
Other post-translational modific of mRNA is 3' tail (Poly A) to protect messenger from degradation and aids in transport to cytoplasm.some mrnAs (like histone mrnas)have no poly A tails., Lastly Intons are spliced just before mRNA goes to cytoplasm.
In short just imagine the mRNA is like a sperm inside the nucleus that puts on a cap(5') for protection and binding, and tail(3') for motility & splices unneseccary accessories (introns ) before going out to the cytoplasm. :wink:
I hope this helps :wink:
Im having a hard time understanding molec bio too.But im TRYING to love it for step1. :lol: heck!
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| asmi
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excellent explanation..
keep it up :idea:
Thanks for nemonic
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