Genome complexity: mRNA function guides (Introduction)

by David Turell , Thursday, September 03, 2020, 20:16 (1324 days ago) @ David Turell

Discovering the structure of mRNA initiation shows how it is guided:

https://phys.org/news/2020-09-protein-mrna-complex-insight-cancer.html

"Although nearly all our cells contain our entire genome, cells use different subsets of genes to make the proteins they need to perform their various functions. This requires precise control over the processes by which the DNA is first transcribed to produce mRNA and then mRNA is translated to make protein.

"Translation begins when a ribosome attaches to a piece of mRNA and scans along it until it finds a start codon, three letters of RNA that say "start translating here." There are over a dozen different proteins known as initiation factors involved in this process.

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"Based on this structure, the researchers proposed a model of how the mRNA slots into a channel in the small ribosomal subunit, and a mechanism for how the mRNA might be pulled through the ribosome for scanning, like a strip of film through an old-style projector.

"They were able to predict that for most mRNAs, the start codon would need to be sufficiently far from the front end of the mRNA for it to be found in the scanning process, which was the confirmed biochemically by Sokabe and Fraser. Further conformation of the model was obtained by mass spectrometry carried out by Mark Skehel of the LMB."

Comment: It is an amazing designed structure, and of course can make mistakes.