Sticky end

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Sticky end (English for “sticky end”) is the name of the end of a DNA segment when one of the two single strands protrudes a few bases beyond the end. If this is the case, another strand of DNA with a complementary sticky end can attach itself to it - hence the name. The opposite - i.e. the end of a DNA double strand without an overhang - is called blunt end (English for "smooth end").

Sticky ends are mainly formed during restriction cuts with certain restriction enzymes .

Example: restriction cut with the enzyme EcoRI

Recognition sequence Restriction cut 
5'-GAATTC-3'
3'-CTTAAG-5'

5'-G       AATTC-3'
3'-CTTAA       G-5'

Since the recognition sequences of the restriction enzymes are palindromic , the two resulting sticky ends are identical.

Sticky ends are usually desired because they enable the targeted linking of DNA strands (see ligation ). For this purpose, the two desired DNA segments are cut out with the same enzyme and thus have matching sticky ends.

literature

  • B. Alberts, D. Bray, J. Lewis, M. Raff, K. Roberts, JD Watson: Molecular Biology of the Cell. 3. Edition. VCH, 1995, ISBN 3-527-30055-4 .