What is most likely to happen in E. coli if a missense mutation disrupts a critical codon in the trpR gene?Group of answer choicesThe trp operon is expressed only when tryptophan is absent.The genes in the trp operon are never expressed.The genes in the trp operon are transcribed but not translatedThe genes in the trp operon are always expressed
Question
What is most likely to happen in E. coli if a missense mutation disrupts a critical codon in the trpR gene?Group of answer choicesThe trp operon is expressed only when tryptophan is absent.The genes in the trp operon are never expressed.The genes in the trp operon are transcribed but not translatedThe genes in the trp operon are always expressed
Solution
The trpR gene in E. coli encodes the Trp repressor, a protein that regulates the expression of the trp operon. The trp operon is a group of genes involved in the synthesis of the amino acid tryptophan.
When tryptophan levels are high, it binds to the Trp repressor, which then binds to the operator region of the trp operon, preventing its transcription and thus the synthesis of more tryptophan.
If a missense mutation disrupts a critical codon in the trpR gene, it could potentially alter the structure and function of the Trp repressor. Depending on the nature of the mutation, it could prevent the repressor from binding to tryptophan or to the operator region, or it could prevent the repressor from being produced at all.
Given the options provided, the most likely outcome of such a mutation would be that "The genes in the trp operon are always expressed". This is because the mutated Trp repressor would not be able to bind to the operator region and inhibit the transcription of the trp operon, regardless of the levels of tryptophan present.
Similar Questions
A missense mutation in the nucleotide sequence of a gene definitely has the effect of: A) The substitution of an amino acid in the protein encoded by the gene B) The production of a protein longer than normal C) The production of a protein shorter than normal D) The death of the cell in which the mutation occurred E) The failure to produce the protein encoded by the gene
A mutation occurs in the operator site within the lac operon of E.coli which prevents binding to the operator of the protein encoded by the lac i gene. What will be the likely effect of this mutation (assume glucose to be absent)? ß-galactosidase will be produced only in the presence of galactose ß-galactosidase will be produced only in the absence of lactose ß-galactosidase will not be produced in significant levels regardless of the presence of lactose ß-galactosidase will be produced continuously regardless of the presence of lactose ß-galactosidase will be produced only in the presence of lactose
A genetic mutation will cause all the following to occur EXCEPT —Select one:a.cause a protein to not have a stop codon.b.create a protein with an incorrect amino acid sequence.c.create a protein with a different mRNA sequence.d.always keep the same shape of the protein.
In a "silent" mutation, theMultiple Choicecodon that mutates causes a change in the amino acid specified.codon that mutates does not cause a change in the amino acid specified.codon that mutates causes a stop codon to occur instead of the placement of an amino acid.mutation does not occur in a codon.mutation is not in DNA.
Which of the following is not a possible effect of a mutation?any of the above can occuradds a function to a proteinlowers the amount of a proteinprevents a protein from forming
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