Inverted repeat
（重定向自Inverted repeats）
![The 5 base-pair sequence on the left is](/Images/godic/202501/20/Inverted-Repeat2059.gif")
![Pseudoknot with four sets of inverted repeats. Inverted repeats 1 and 2 create the stem for stem-loop A and are part of the loop for stem-loop B. Similarly, inverted repeats 3 and 4 form the stem for stem-loop B and are part of the loop for stem-loop A.](/Images/godic/202501/20/Pseudoknot-Inverted-Repeats2059.gif")
![](/Images/godic/202501/20/Ribo100r2100.gif")
![Inverted repeat changing to/from an extruded cruciform. A: Inverted Repeat Sequences; B: Loop; C: Stem with base pairing of the inverted repeat sequences](/Images/godic/202501/20/DNA_palindrome.svg2100.png")
An inverted repeat (or IR) is a sequence of nucleotides followed downstream by its reverse complement. The intervening sequence of nucleotides between the initial sequence and the reverse complement can be any length including zero. When the intervening length is zero, the composite sequence is a palindromic sequence.