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

bioinformatics.stackexchange.com

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

#31

Post by koheripbal »

FormerBandmate wrote: post #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…

Interestingly, vaccines also have a long repeating sequence at the end. It provides molecular stability.

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

#33

Post by roenxi »

File formats are really easy to figure out and are a big advantage for moving data around. Even without an academic theory, pretty much everyone in software starts to figure out the same tricks as soon as reliable transmission becomes a goal. I assume that at least one reason for this is that genomes are data, data likes to live in structured formats, and file terminators are more reliable for biology to process than encoding the length of the genome (although, biology being messy, I wouldn't be shocked if both were done). Evolution has a good grasp of engineering principles.

Are there probably desirable chemical properties? Yes. Is nature overloading each part of a genome with uses? More than likely. Has it figured out how to terminate a sequence? Obviously.

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

#34

Post by qclibre22 »

ramesh31 wrote: post #28
FormerBandmate wrote: post #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 biological equivalent of an endline

The stop codon is more like the '\n' or '\0' in computing. Polya tails protect against degradation and is used for nuclear export of RNA.

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

#40

Post by rightbyte »

dogma1138 wrote: post #27
luckylion wrote: post #9

Earlier quoted context omitted.

Had it started with aaaaaaaaaaaaa, I would've put my money on someone optimizing for the virus yellow pages.

Isn't the start and end of a genome is rather arbitrary?

Doesn't the replication have a direction though? I.e. start and end.
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