Question

A particular protein (Vac8) found in yeast has this N-terminal sequence, Met-Gly-Ser-Ser-Cys.... The corresponding DNA sequence in the coding strand is 5' ATG GGC TCA TCG TGC.... If the DNA sequence is mutated to 5' CTG GGC TCA TCG TGC..., what will happen to this VAC8 gene? (in RNA, CUG codes for Leu)

Answer 1

Answer:

The protein will not be synthesized because this point mutation produces the loss of the start codon (substitution of Met by Leu).

Explanation:

The mutations are changes in the DNA sequence that have diverse effects on protein synthesis. A mutation in the start AUG codon may lead to the reduction and even the elimination of protein synthesis. In consequence, this type of point mutation is usually referred to as 'start-loss mutation'.