Final answer:
A nonsense mutation results in a premature stop codon, creating a truncated protein, but secondary mutations can act as suppressors to prevent this truncation. These suppressor mutations enable the production of full-length proteins despite the initial mutation. DNA damage suppressors are essential in protecting organisms from harmful mutations that could potentially truncate proteins.
Step-by-step explanation:
A nonsense mutation is a type of genetic mutation in which a codon that originally specified an amino acid is changed to a premature stop codon. This results in the production of a truncated and potentially nonfunctional protein. However, in some cases, second mutations elsewhere in the genome can suppress the effects of a nonsense mutation.
Suppressor mutations are a genetic phenomenon that prevents the truncation of proteins that nonsense mutations would usually cause. When the protein truncation is suppressed, the organism can survive despite the initial damaging mutation. Such suppression often involves the production of a tRNA that can recognize the stop codon as a codon for an amino acid, thereby allowing the translation process to continue and produce a full-length protein.
Although DNA damage suppressors are generally recessive alleles, which contain loss-of-function mutations, they serve a crucial role in protecting organisms from mutations that could truncate proteins and compromise genetic integrity. Cancer research has highlighted the importance of understanding how mutations, including nonsense and frameshift mutations, affect the function of tumor suppressor genes and proto-oncogenes.