How does the haeiii enzyme discriminate between the c-g polymorphism in the tas2r38 gene?

Answer;

-HaeIII cuts at the sequence GG:CC which is found at nucleotide 143-146 of the TAS2R38 gene. A non-taster alley changes the sequence at position 145 from a C to a G. This makes the gene no longer recognized by the restriction enzyme.

Explanation;

-Restriction enzymes recognize and make a cut within specific palindromic sequences, known as restriction sites, in the genetic code. This is usually a 4- or 6 base pair sequence.

For example; HaeIII is a restriction enzyme that searches the DNA molecule until it finds this sequence of four nitrogen bases.

5’ TGACGGGTTCGAGGCCAG 3’

3’ ACTGCCCAAGGTCCGGTC 5’

Once the recognition site was found HaeIII could go to work cutting (cleaving) the DNA