The wild type puffy protein in yeast is exactly 103 amin aci

The wild type \"puffy\" protein in yeast is exactly 103 amin acids long. The amino-terminal portion of the wild type \"puffy\" protein has the following amino acid sequence (NH2-met-trp-his-tyr-met-gly-cys-tyr-pro-leu-lys-...) B) A mutant yeast cell (Mutant #1) was found that does not synthesize the \"puffy\" protein. Instead this mutant cell synthesizes a new peptide that is related to \"puffy\" but this new peptide is only 6 amino acids long and is not found in wild type cells. This peptide has the amino acid sequence (NH2-met-typ-his-tyr-met-gly-COOH. A) what is the specific molecular basis of the mutation in Mutant 1(what is the specific change in the DNA that caused the synthesis of this mutant protein)? Show how you reached your conclusion. Please include the DNA sequence before and after the mutation

Solution

A. The type mutation occurred in the mutant 1 is called as Nonsense mutation where there is a change in one DNA base pair where the substitution of one amino acid for another leads to premature termination of protein due to the introduction of a stop codon.

The amino acid after which the protein got terminated is glycine and after which the wild type yeast has Cysteine amino acid which has a codon UGC/UGU, when this codon is mutated to UGA it leads to termination of the protein as it codes for a stop codon.

Before mutation: NH2-met-trp-his-tyr-met-gly-UGC/UGU-tyr-pro-leu-lys-..

After mutation: NH2-met-trp-his-tyr-met-gly-UGA-COOH