Inverted repeats are close cousins of palindromes. Note having palindromic sequences along short the short stretches over which restriction enzymes function is not common. An exact palindrome is one in which there is no asymmetry in the centre or mismatch in any part of the sequence, such that its reverse compliment reads the same as the original sequence itself 3. Having short stretches of DNA that read the same on both strands of double-stranded DNA allow restriction enzymes to cut both strands in the same place. Calculate the reverse complement of the whole forward strand to finish the reverse strand: ATCGAT.Reverse the order of the reverse complement ( CTA) and add it to the end of the forward strand - TAGCTA.Calculate the reverse complement of the sequence - ATC.Starting with the original sequence - TAG.TAGCTA) can be reconstructed from just knowing the first three bases on one strand: For example, a six-base recognition sequence (e.g. This pattern makes it possible to reconstruct a palindromic sequence from one-half of one strand. The complement to the whole six base strand is CCTAGG, read backwards (as it would be when reading from 5’ to 3’ on the complementary strand) is GGATCC, an exact match for the original strand. A palindrome in DNA is like a palindrome in language, but when read backwards, it is a complement of the forward sequence effectively, the two halves of a sequence complement each other. Note the first three bases GGA are followed by the complement of those three bases in reverse order: TCC. For example the recognition sequence for BamHI is GGATCC. The palindromic sequence is important in genetic engineering because it makes insertion and amplification easier. Palindromic sequences are a short run of bases (typically 3 to 5 in length), follow by their complementary bases in reverse order. They are probably more properly referred to as palindromic sequences to distinguish them from language palindromes. Many restriction endonucleases (restriction enzymes) recognize specific palindromic sequences and cut them. Because a DNA sequence is double stranded, the base pairs are read, (not just the bases on one strand), to determine a palindrome. In English, the term palindrome refers to a string of letters that have the same meaning written in both directions some classic English palindrome are kayak, civic, noon, and racecar.Īs a set of paired sequences (one on each of the strands of a double strand of DNA), the palindromes recognized by restriction enzymes follow a slightly different set of rules. Palindromic sequences play an important role in molecular biology.

Importance of palindromic sequence