Restriction enzymes

Restriction enzymes work by recognizing a particular sequence of bases on the DNA. The enzyme then cuts the DNA's backbones, allowing the DNA to separate into two pieces.

For example, the enzyme EcoRI (see the figure) binds to the sequence GAATTC and cuts between the G and the A. It also cuts between the A and the G on the complementary strand.

All parts in the Registry of Standard Parts are standardized by having "biobrick ends" composed of restriction sites in the order of EcoRI-NotI-Xba on the left side of the insert and SpeI-NotI-PstI on the right side.

• For the whole story on restriction enzymes, visit here
• For more information on the biobricks standard assembly, visit here
• When faced with the task of analyzing long sequences of DNA for restriction sites, software is available to search DNA for recognition sequences. One such useful program is [http://tools.neb.com/NEBcutter2/index.php NEB cutter], which interfaces the New England Biolab's library of restriction enzymes.