The uncharged MutA tRNA possesses complementarity to a region in the 5'end of the " dnaQ " mRNA . This allows it to act as an antisense mRNA that directs the degradation of the dnaQ transcript and thus, a lower abundance of the subunit and increased frequency of mutation.
22.
From 1963 until 1966, he studied the mutagenesis of T2 bacteriophage at high doses of UV and gamma irradiation ., He also studied the phenomenon of the maximum of frequency of mutations at high doses of radiation and suggested an explanation for this phenomenon based on the consecutive damage of nucleotide codons in the genes.
23.
This is shown in the figure at the 4th level from the top . ( In the figure, red wording indicates the central role of DNA damage and defects in DNA repair in progression to cancer . ) When DNA repair is deficient DNA damage remains in cells at a higher than usual level ( 5th level ) and cause increased frequencies of mutation and / or epimutation ( 6th level ).
