The following sequences represent partial peptide sequence r

The following sequences represent partial peptide sequence results from a wild-type protein and two mutant versions of the same protein. \"...\" Indicates the presence of amino acids for which the sequence was not determined.

Wild-type met-pro-trp-ala-ser

Mutant #1 met-pro

Mutant #2 met-pro-met-gly-leu-leu....

What type of mutation gave arise to mutant #1?

What type of mutation gave arise to mutant #2?

Solution

Mutant #1 - Met-Pro The first type of mutant is Nonsense Mutation which is a point mutation in a DNA sequence that leads to presence of premature stop codon. Due to this the DNA sequence becomes truncated and the formation of the chain is incomplete. In this process or type of mutation, due to premature stop codon, the amino acid is not added further leading to truncated DNA sequence.

Mutant #2 - It is frameshift mutation that leads to change in the gene sequence due to addition or deletion in the nucleotides. Addition of extra nucleotide or deletion leads for formation of different codon and hence the sequence of DNA changes post the frameshift mutation.