Transcript Restriction Enzymes Notes

Restriction Enzymes
•
•
•
Enzymes that CUT
DNA at a specific
nucleotide sequence
May produce
blunt ends or
sticky ends.
Sequence cut is a
palindrome - same
letters forward and
backwards!
Blunt End Cuts
• Used to isolate a
fragment of DNA
• Used to cut DNA into
pieces for DNA
fingerprinting
Sticky End Cuts
• Used when one DNA
fragment is combined
with another DNA
fragment to make
RECOMBINANT
DNA
• Allow complementary
base pairs to join
together.
Where do Restriction Enzymes
come from?
• Found in bacteria
• Enzymes are used to
cut and degrade
viruses that enter their
cells
• Named for species in
which R.E. was found
• Example: EcoR1 was
first R.E. to be
isolated from E. coli
Picture of the protein molecule
Sequence of bases cut by
EcoR1
Practical Applications
• Gene for human
insulin or human
growth hormone
placed into a bacterial
plasmid.
• Gene for disease
resistance placed into
DNA in cells of a corn
plant
What’s next?
• We will use this
information to model
the genetic
engineering of the
hormone, insulin
• You will choose the
best restriction
enzyme to cut out the
insulin gene and place
it into the bacterial
plasmid