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What is a shift in the reading frame?
Definition: A genetic mutation caused by indels (insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three. Codon.
What maintains the reading frame?
The ribosome must ensure that the binding of the tRNAs remains faithful to the codon of the mRNA displayed at the A site and that the correct reading frame of the mRNA is maintained during translation (reviewed by Wilson and Nierhaus, 2003).
Which is a silent mutation?
Silent mutations are mutations in DNA that do not have an observable effect on the organism’s phenotype. They are a specific type of neutral mutation. The phrase silent mutation is often used interchangeably with the phrase synonymous mutation; however, synonymous mutations are not always silent, nor vice versa.
What is the result of a frameshift mutation?
Therefore, frameshift mutations result in abnormal protein products with an incorrect amino acid sequence that can be either longer or shorter than the normal protein.
Why are there six reading frames?
The longer an open reading frame is, the longer you get before you get to a stop codon, the more likely it is to be part of a gene which is coding for a protein. So it’s actually six different reading frames for every piece of DNA, which might give you an open reading frame.
What causes a change in the reading frame?
The change in DNA sequence can occur either at a particular point or over a region of the sequence. The change causes a shift in the reading frame to produce a different product. Besides, frameshift mutation can also occur via induced mutation in the presence of physical agents like X-ray and UV radiation.
When does mRNA read out of frame in frameshift mutation?
Because the reading frame begins at the start site, any mRNA produced from a mutated DNA sequence will be read out of frame after the point of the insertion or deletion, yielding a nonsense protein. Similarly to a point mutation, a frameshift mutation can produce a termination codon (Fig. 17-7).
Which is an example of a frame shifting event?
However, multiple and in part isolate-dependent frame shifting events, as well as internal translation initiation events, have also been reported. Detection of antibodies and T cells specific for the ARFP/F proteins in patients with hepatitis C suggests that these proteins are expressed during infection.
What happens when a mutation disrupts one of the reading frames?
If a mutation disrupts one of those reading frames, so that the wrong amino acid is put in place, then the entire DNA sequence following the mutation will be disrupted or read incorrectly. Very often, what we see is a premature termination.