Question

What would happen if in a gene encoding polypeptide of 50 aminoacids 25th codon (UAU) is
mutated to UAA ?Explain.

Answer 1

UAA is one of the stop codons (besides UAG and UGA). Point mutation in a sequence of DNA that results in a premature stop codon is referred to as a nonsense mutation. In our case mutation results in truncated 24-amino acid peptide, starting from the first amino acid as usual and ending before the premature stop codon.