Which type of mutations usually involves mutation of a gene coding for a following molecule?

A nonsense suppressor mutation is a secondary muta­tion that reverses the effect of a primary nonsense or chain-termination mutation. Ordinarily, no transfer RNA (tRNA) molecule can recognize a nonsense co­don; therefore, protein synthesis terminates when the ribosome reaches such a codon. A nonsense suppressor mutation usually involves the mutation of a tRNA gene, so that the anticodon of the tRNA is altered to a sequence that is complementary to a nonsense codon. The altered tRNA can then bind to the nonsense codon and insert an amino acid at that point in the protein sequence. Thus, protein synthesis is allowed to continue, and the nonsense mutation is suppressed. A silent mutation is one that causes no change in the amino acid sequence of a protein. A missense mutation causes a single amino acid change. A frameshift mutation is the result of an insertion or deletion that alters the reading frame of the ribosome, leading to the production of a garbled amino acid sequence.