Question

A strain of yeast translates mRNA into protein with a high level of inaccuracy. Individual molecules of a particular protein isolated from this yeast have the following variations in the first 11 amino acids compared with the sequence of the same protein isolated from normal yeast cells normal sequence Met Trp Ala Ile Val Ser Trp Thr Gin Ile Lys variants Met Cys Ala Ile Val Ser Trp Thr Gln Ile Lys Met Trp Ala Ile Val Ser Cys Thr Gin Ile Lys Met Cys Ala Ile Val Ser Trp Thr Gin Ile Lys Met Trp Ala Ile Val Ser Cys The Gin Ile Lys Met Cys Ala Ile Val Ser Tep Thr Gin Ile Lys Met Trp Ala Ile Val Ser Cys The Gin Ile Lys What is the most likely cause of this variation in protein sequence? O A mutation in elongation factor to that decreases the accuracy of codon-anticodon recognition. O A mutation in the spliceosome that leads to inaccurate RNA splicing. A mutation in the tryptophan-CRNA synthetase that decreases its ability to distinguish between different tRNA molecules. A mutation in the anticodon of the cysteine tRNA (ERNACys). O A mutation in the tryptophan-tRNA synthetase that decreases its ability to distinguish between different amino acids.

Answer 1

Question

The likely cause of variation is mutation in the tryptophan -tRNA synthetase that decreases it's ability to distinguish between different amino-acid. This is because mutation in the tryptophan -tRNA synthetase will lead to its pairing with tryptophan Codon and cause a variety of substitutions occupied by tryptophan. The option c is incorrect because this mutation will lead to the substitutions of amino-acid would take place at many amino acid and not only to tryptophan. Hence, option e is correct.