Imagine a person who is infected with HIV. Let\'s call him John. This happened i
ID: 255360 • Letter: I
Question
Imagine a person who is infected with HIV. Let's call him John.
This happened in the early 1990s, when treatments weren't so good yet.
On Jan 1st, he starts treatment, the amount of virus in his blood goes down.
On Feb 1st, one viral particle in his blood acquires a resistance mutation (M184V in
Reverse Transcriptase).
Between Feb 1st and March 1st, the population of resistant virus grows
exponentially in John's body. On March 1st, all his virus carries the M184V mutation.
1C. Which codon (triplet) could have coded for the M in M184V and which could
have coded for the V in M184V? Which nucleotide must have mutated?
Explanation / Answer
This mutation is caused by the substitution of Methionine amino acid at 184th location of reverse transcriptase protein sequence with Valine amino acid.
The Methionine is coded by ATG. Valine is coded by 4 possible triplets. The change from GTG to ATG in Valine triplet causes easier and simplest mutation. So amino acid from Methionine changed to Valine due to change in triplet GTG to ATG.