Question

Write the palindromic nucleotide sequence for the following sequence of DNA segment: 5’–GAATTC–3’.

Hint:

Palindromic sequences are targets for restriction enzymes; they read the same on both strands in the 5’ to 3’ direction.

Answer 1

Step 1: A palindromic sequence in DNA reads the same on both strands in the 5’ to 3’ direction when considering complementary base pairing.
Step 2: The given sequence is 5’–GAATTC–3’. Its complementary strand (3’ to 5’) is determined by base pairing: G pairs with C, A with T, T with A, etc.
Step 3: Complementary strand (3’ to 5’): 3’–CTTAAG–5’. When read in the 5’ to 3’ direction, the complementary strand is 5’–GAATTC–3’, which matches the original sequence.
Step 4: Thus, the palindromic sequence is:
5’–GAATTC–3’
3’–CTTAAG–5’
This is a palindromic sequence because both strands read 5’–GAATTC–3’ in their respective directions.