Confused about operons (cluster of genes)

[zut212]

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According to Wiki: "The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product. "

Suppose that the genes are translated into one protein, and this protein has the sequence like this: ABCDZYXWEFGH.

Alternatively, the protein's code can be trans-spliced as into 3 proteins: ABCD, ZYWX, EFGH.

However, the first megaprotein of 12 amino-acids should be very different than the 3 smaller amino-acids of 3 amino-acids.

How is transcribing/translating many genes at once beneficial if the two alternative manifestations are VERY different?

 

[Rabolisk]

Post-translational modifications, maybe.

 

[chimparmy]

In terms of viral translation, it is beneficial (depending on the virus) to be able to produce many different proteins from a single piece of mRNA since a viral capsid can only store so much nucleic acid. I think of it as a space saving mechanism. I am not sure if this answers your question.

 

[ten pound]

According to Wiki: "The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product. "

Suppose that the genes are translated into one protein, and this protein has the sequence like this: ABCDZYXWEFGH.

Alternatively, the protein's code can be trans-spliced as into 3 proteins: ABCD, ZYWX, EFGH.

However, the first megaprotein of 12 amino-acids should be very different than the 3 smaller amino-acids of 3 amino-acids.

How is transcribing/translating many genes at once beneficial if the two alternative manifestations are VERY different?

The transcription and translation wouldn't be random. Operons usually have complex regulatory mechanisms. Those regulatory mechanisms allow the organism to vary the expression of genes depending on environmental conditions, increasing it's survivability. So the organism could express ABCDZYXWEFGH only went it's hot or ABCD if it detects high sodium levels etc. That's the advantage of having an operon.

 

[TXKnight]

The transcription and translation wouldn't be random. Operons usually have complex regulatory mechanisms. Those regulatory mechanisms allow the organism to vary the expression of genes depending on environmental conditions, increasing it's survivability. So the organism could express ABCDZYXWEFGH only went it's hot or ABCD if it detects high sodium levels etc. That's the advantage of having an operon.

Think lac operon