Insertion sequence

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An insertion sequence (also known as an insertion element, an IS, an insertion sequence element, an IS element, or an IS sequence) is a short DNA sequence that acts as a simple transposable element; insertion sequences only code for transposition enzymes (transposases). The transposase coding region in an insertion sequence is usually flanked by inverted repeats. Insertion sequences are generally around 700 to 2500 bp in length. A particular insertion sequence may be named according to the form ISn, where n is a number (e.g. IS1, IS870, IS31831, etc.); this is not the only naming scheme used, however. Although insertion sequences are usually discussed in the context of prokaryotic genomes, certain eukaryotic DNA sequences may be considered to be insertion sequences. [1]

In addition to occurring autonomously, insertion sequences may also occur as parts of composite transposons; in a composite transposon (also known as a "complex transposon" or sometimes simply referred to as a "transposon"), two insertion sequences flank one or more non-transposition genes.

[edit] See also

Mobile genetic elements

[edit] References

Campbell, Neil A. and Reece, Jane B. (2002). Biology (6th ed.), pp. 345-346. San Francisco: Benjamin Cummings. ISBN 0-8053-6624-5.
Mahillon, Jacques and Chandler, Michael (1998). "Insertion sequences". Microbiology and Molecular Biology Reviews 62 (3), 725-774. Retrieved January 11, 2006.
Prescott, Lansing M.; Harley, John P.; and Klein, Donald A. (2002). Microbiology (5th ed.), pp. 298-299. New York: McGraw-Hill. ISBN 0-07-232041-9.
Shuler, Michael L. and Kargi, Fikret (2002). Bioprocess Engineering: Basic Concepts (2nd ed.), p. 220. Upper Saddle River, NJ: Prentice Hall PTR. ISBN 0-13-081908-5.