What would be the consequence of one nucleotide deletion in

What would be the consequence of one nucleotide deletion in the chromosome at the following locations:

a. Just before a gene (~10 bp upstream)

b. In the start codon

c. ~30 bp after the start codon

Solution

A. If a nucleotode is deleted just before a gene or -10 base pair upstream.,it is the promoter region of the gene where RNA polymerase binds to promoter to start the transcription process. If a nucleotide os deleted from here, tje promoter recogniyion sequence will not be ae to recognise promoter and transcription process will not start.

B. If a nucleotide is deleted from the start codon, the sequence of start codon will change. AUG is the start codon which binds to the translation start site, and initiates the process of translation or protein symthesis. Deletion will lead to arrest of translation initiation.

C. Nucleotide deletion at 30 bp of nucleotides will lead to change in the reading freame of codons and it will lead to frameshift mutation due to which, some faulty or another or truncated protein or polypeptide chain will be formed..

for example: After 30 bp nucleotide sequence is : AGGCCCUACAUGGUCCUU, it will code a particular chain of amino acid. If G From 3rd position.is deleted,,the new reading frame will be AGC CCU ACA UGG UCC UU. This is frameshift mutation.