In a Mutant E

question 16

Multiple Choice

In a mutant E. coli strain, there was a mutation in the malate dehydrogenase gene that resulted in a stop codon at amino acid position #14. From subcultures of this strain, a colony was obtained that was capable of making malate dehydrogenase. Your approach to examining this phenomenon should be to examine

• A)the DNA and plasmids for the incorporation of a second complete copy of the malate dehydrogenase gene.
• B)the DNA sequence to see if a suppresor mutation has occurred.
• C)other proteins to see if other stop codons are ignored, indicating the presence of a suppresor tRNA.
• D)the DNA sequence to see if a reversion has occurred.
• E)all of the above