A protein that cleaves a DNA sequence at a specific point. There
are 3 different kinds of Restriction Enzyme, with the most
commonly used in molecular biology being Type II. This type of
restriction enzyme cleaves pallandromic DNA sequences in double
stranded DNA. For example, the enzyme EcoRI cleaves the
following sequence: to give two sticky ends 5'-G
AATTC-3' 3'-CTTAA         G-5' Their function in nature is to
protect bacteria from foreign DNA by chopping it into small
fragments, which generally are not harmful. Bacteria prevent
chopping their own DNA by methylation of self strands. Also
known as: Restriction Endonucleases  See Also: DNA
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