Can someone please expain to me the following question for me. I\'m really confu
ID: 174716 • Letter: C
Question
Can someone please expain to me the following question for me. I'm really confused on how to apporach it. Like I know I need to pick between mutant A & B to see which one gives me rII- plaques and I quickly know that mutant B disrupts the His-Glu-Asp activity by converting the GAA of the WT to a UAA. Now from here how do I know if I plate it in lawn of Bac1 or 2? I'm really confused about that. Any help will be much appreaciated!
11. Below is the RNA sequence from the imaginary coding region of the rIIB gene of bacteriophage T4. The gene encodes a 6 aa protein. The His-Glu-Asp is all that is required for rII+ activity. You isolated two mutations in this gene: WT 5' GACUGA AUG UUU. UCA. CAU GAA. GAC UAAUUAG 3 Met Phe Ser His Glu As Stop MutA 5, GACUGAAUG.UUU. UAA CAU GAA GAC. UAAUUAG 3 MutB 5' GACUGAAUG.UUU. UCA. CAU. UAA GAC UAAUUAG 3 You also have two E. coli strains with a tRNA mutation: In Bacl, a mutation changes a tRNA anticodon from 3'AGUS' to 3'AUU5'. In Bac2, a mutation changes a tRNA anticodon from 3 'CUUS' to 3'AUTU5 Which of the following will produce large GrII plaques? A. Phage MutA on a lawn of Bac 1 B. Phage MutA on a lawn of Bac 2 C. Phage MutB on a lawn of Bac 1 D. Phage MutB on a lawn of Bac 2 E. More than one of the above.Explanation / Answer
WT mRNA - AUG UUU UCA CAU GAA GAC UAA
WT tRNA - UAC AAA AGU GUA CUU CUG AUU
WT AA - Met Phe Ser His Glu Asp Stop codon
1) Mut A mRNA - AUG UUU UAA CAU GAA GAC UAA
Bac1 tRNA - UAC AAA AUU GUA CUU CUG AUU
Mut1 AA - Met Phe Stop
2) Mut B mRNA - AUG UUU UCA CAU UAA GAC UAA
Bac2 tRNA - UAC AAA AGU GUA AUU CUG AUU
Mut2 AA - Met Phe Ser His Stop
3) Mut B mRNA - AUG UUU UCA CAU UAA GAC UAA
Bac1 tRNA - UAC AAA UUA GUA UUC CUG AUU
Mut1 AA - Met Phe Asn His Lys Asp Stop
By wobble hypothesis, If A is at the 3rd position in the codon it can base pair with U in the 1st position of the anticodon
If U is at the 3rd position in the codon it can base pair with A, G in the 1st position of the anticodon
If G is at the 3rd position in the codon it can base pair with C or U in the 1st position of the anticodon
If C is at the 3rd position in the codon it can base pair with G in the 1st position of the anticodon.
That is 3 of mRNA recognises 1 of tRNA.
answer : C
Mut B and Bac 1 gives large rII- plaques