An inverted repeat is a sequence of nucleotide

Nucleotide

Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...

s that is the reversed complement

Complementarity (molecular biology)

In molecular biology, complementarity is a property of double-stranded nucleic acids such as DNA, as well as DNA:RNA duplexes. Each strand is complementary to the other in that the base pairs between them are non-covalently connected via two or three hydrogen bonds...

 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

Palindrome

A palindrome is a word, phrase, number, or other sequence of units that can be read the same way in either direction, with general allowances for adjustments to punctuation and word dividers....

. Inverted repeats define the boundaries in transposon

Transposon

Transposable elements are sequences of DNA that can move or transpose themselves to new positions within the genome of a single cell. The mechanism of transposition can be either "copy and paste" or "cut and paste". Transposition can create phenotypically significant mutations and alter the cell's...

s. Inverted repeats also indicate regions capable of self-complementary base pairing (regions within a single sequence which can base pair with each other).

Examples

• original: 5'-GACTGC-3'
• complement: 3'-CTGACG-5' (base pairing)
• reverse complement: 5'-GCAGTC-3'
• lac operator: 5'-AATTGT...ACAATT-3'

External links

• Inverted Repeats Database (IRDB)
• Genome Atlas Database — contains hundreds of examples