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You are studying a yeast mutant where the CTD tail of RNA Po…

You are studying a yeast mutant where the CTD tail of RNA Pol II has several key serines (phosphorylatable amino acids) converted to alanines (non-phosphorylatable). The result of these changes is the failure of polyA polymerase (PAP) to bind during transcription. The resulting RNA polymerase protein would most likely  be capable of synthesizing:

You are fascinated by the biochemical pathway that leads to…

You are fascinated by the biochemical pathway that leads to the biosynthesis of the amino acid Arginine that we learned about in the Beadle Tatum experiment. You mutagenized E. coli, and identified an Arginine auxotroph in which the mutation maps to Gene 3 encoding the Enzyme 3 that converts Citrulline to Arginine. You find the Gene 3 mutation resulted in a deletion of an inverted repeat sequence occurring 5′ (upstream) to a GT-rich sequence at the 3′ end of the gene.  Further examination shows that the gene is able to be transcribed but no protein is made (hence it being an auxotroph for Arginine). Based on these data, your most likely prediction would be:

You are studying a yeast mutant where the CTD tail of RNA Po…

You are studying a yeast mutant where the CTD tail of RNA Pol II has several key serines (phosphorylatable amino acids) converted to alanines (non-phosphorylatable). The result of these changes is the failure of polyA polymerase (PAP) to bind during transcription. The resulting RNA polymerase protein would most likely  be capable of synthesizing: