Inverted repeat

An inverted repeat (or IR) is a sequence of nucleotides that is the reversed complement of another sequence further downstream. For example, 5'---GACTGC....GCAGTC---3'. When no nucleotides intervene between the sequence and its downstream complement, it is called a palindrome. Inverted repeats define the boundaries in transposons. Inverted repeats also indicate regions capable of self-complementary base pairing (regions within a single sequence which can base pair with each other). Also compare with direct repeats.

Examples

 * original: GACTGC
 * complement: CTGACG (base pairing)
 * reverse complement: GCAGTC (read backwards)