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Why does the SARS-Cov2 genome end in aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa? (2020)

bioinformatics.stackexchange.com

11–20 of 125 posts

Re: Why does the SARS-Cov2 genome end in aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa? (2020)

#13
I don't think this is nearly as true for virii genomes, but larger species have lots of protetive sections of DNA to protect from mutations. If you lose a non-protein-coding section of DNA to mutation, no harm to the species occurs. In humans, only about 1.5% of our DNA codes for protein that is actually generated. Virii are physically extremely tiny in terms of cell size and must be very efficient in terms of storing the DNA within them so way more actually codes, but no doubt there are similar factors at play.

Re: Why does the SARS-Cov2 genome end in aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa? (2020)

#15
The top answer at the link explains it best:

Good observation! The 3' poly(A) tail is actually a very common feature of positive-strand RNA viruses, including coronaviruses and picornaviruses.

For coronaviruses in particular, we know that the poly(A) tail is required for replication, functioning in conjunction with the 3' untranslated region (UTR) as a cis-acting signal for negative strand synthesis and attachment to the ribosome during translation. Mutants lacking the poly(A) tail are severely compromised in replication.

Re: Why does the SARS-Cov2 genome end in aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa? (2020)

#17
post #16

Maybe the scientist who made it died before he finished? ATTACGAAAAAAAAAAAAAAAAAAAAAAAA……

Look, if he died while engineering a virus, he wouldn't bother to code "AAAAAAA" he'd just say it!

Well that's what it says.

Re: Why does the SARS-Cov2 genome end in aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa? (2020)

#18
post #13

I don't think this is nearly as true for virii genomes, but larger species have lots of protetive sections of DNA to protect from mutations. If you lose a non-protein-coding section of DNA to mutation, no harm to the species occurs. In humans, only about 1.5% of our DNA codes for protein that is actually generated. Virii are physically extremely tiny in terms of cell size and must be very efficient in terms of storin…

Viral genomes are very compressed. In fact, viruses usually have overlapping genes, where one genomic region can codify for more than one product. See the following review for more information: https://www.nature.com/articles/s41576-021-00417-w

Re: Why does the SARS-Cov2 genome end in aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa? (2020)

#20
post #16

Earlier quoted context omitted.

Look, if he died while engineering a virus, he wouldn't bother to code "AAAAAAA" he'd just say it!

Well that's what it says.

Perhaps he was dictating?

https://www.youtube.com/watch?v=ZlIz0q8aWpA

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