Shown here are the amino acid sequences of the wild-type and three mutant forms of a short protein. Use this information to answer the following questions:
Wild type: mer-trp-tyr-arg-gly-ser-pro-thr
Mutant 1: met-trp
Mutant 2: met-trp-his-arg-gly-ser-pro-thr
Mutant 3: met-cys-ile-val-val-val-gln-his
Using Figure 13-7, predict the type of mutation that occurred leading to each altered protein.
For each mutant protein, determine the specific ribonucleotide change that led to its synthesis.
The wild-type RNA consists of nine triplets. What is the role of the ninth triplet?
For the first eight wild-type triplets, which, if any, can you determine specifically from an analysis of the mutant proteins? In each case, explain why or why not.
Another mutation (Mutant 4) is isolated. Its amino acid sequence is unchanged, but mutant cells produce abnormally low amounts of the wild-type proteins. As specifically as you can, predict where in the gene this mutation exists.
