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)

See also

• Stem-loop

External links

• Inverted Repeats Database (IRDB)
• Genome Atlas Databse — contains hundreds of examples
• Inverted+Repeat+Sequence at the U.S. National Library of Medicine Medical Subject Headings (MeSH)