When an extra nucleotide is inserted into DNA in a specific mutation, which results a protein in which most amino acids after the site of insertion are changed. When a mutation occurs by the deletion or insertion of one more nucleotides in a DNA sequence, is referred as frame shift mutation.
The DNA sequence possesses many nucleotides that are read in three nucleotide sequences called codons, and each codon relates to a particular amino acid or stop signal. Throughout translation, codons containing sequences is read in an order from the nucleotide sequence to produce a protein.
The suppressor mutation particularly suppresses frame shift mutation by altering the phase of translation. Frame shift suppressors are mutant tRNA (transfer ribonucleic acid) molecules containing a four base anticodon rather than the usual three base anticodons. The tRNA molecule reads the four base codons instead of three base codons and will re-adjust the reading frame correctly and permit protein synthesis.
Change in ribosome structure is due to the mutation in ribosomal proteins that misread the mRNA (messenger ribonucleic acid) codons is called ribosomal ambiguity (ram), which has the ability of reading all the three termination codons therefore initiating suppression of nonsense mutations. Certain frameshift mutations may also be suppressed by these ram mutants.