2. What Are Restriction Enzymes?
• Enzymes that are produced by different kinds
of bacteria that can cleave or cut DNA strands
at a specific sequence of nucleotides
http://www.google.com/imgres?nu
m=10&um=1&hl=en&biw=1015&bih
=738&tbm=isch&tbnid=_oThF_Vt0n
85gM:&imgrefurl=http://www.web-
books.com/MoBio/Free/Ch9A3.htm
&docid=grGZk3ryZHYEpM&imgurl=h
ttp://www.web-
books.com/MoBio/Free/images/Ch9
At.gif&w=571&h=434&ei=0pO9T9Ph
Gc_16gHh2IhZ&zoom=1&iact=hc&v
px=90&vpy=357&dur=1241&hovh=1
96&hovw=258&tx=179&ty=109&sig
=103128700879282556508&sqi=2&
page=1&tbnh=120&tbnw=158&start
=0&ndsp=15&ved=1t:429,r:10,s:0,i:
167
3. Types of Restriction Enzymes
• Type I: Random cuts occur at locations that
could be thousands of nucleotides apart
• Type III: Cuts are as long as around 25
nucleotides
• Type II: This type is most used in Biology – cuts
occur about every 4-6 nucleotides
4. Types of Cleaving
• Blunt End: Enzyme • Sticky End: Enzyme
cuts straight through cuts closer to each
side of the
recognition sequence.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/RestrictionEnzymes.html
5. Discovery
• Werner Arber & Stuart Linn discovered
Restriction Enzymes
• 1st Restriction Enzyme that was discovered
was EcoB
– This came from a strain of E. coli
– Soon after this discovery, EcoK was discovered
from E. coli as well
6. Recombinant DNA Process
• In this process, bacterial DNA is joined with a
gene of interest
• This process is performed in order to study
the DNA more thoroughly or for useful
products like vaccines
7. Recombinant DNA Process Steps
1. DNA from the organism of interest is
prepared to be able to be cloned
2. A virus is digested with and enzyme and
compatible ends (with the DNA) are made
3. DNA in a plasmid form is cut
4. This DNA is joined with the virus’ compatible
ends
5. The DNA strands are joined with DNA ligase
8. Recombinant DNA Process http://www.google.com/i
mgres?num=10&um=1&h
l=en&biw=1015&bih=73
8&tbm=isch&tbnid=ht1Y
nB2I-
Plasmid is cut here 9Q5HM:&imgrefurl=http:
//en.wikipedia.org/wiki/Re
combinant_DNA&docid=
KUT-
5jVGGyn4zM&imgurl=ht
tp://upload.wikimedia.org/
wikipedia/en/thumb/0/01/
Recombinant_formation_
of_plasmids.svg/280px-
Recombinant_formation_
of_plasmids.svg.png&w=
280&h=227&ei=xJe9T6D
oELON6QHcvZhe&zoom
=1&iact=hc&vpx=127&v
py=201&dur=204&hovh=
181&hovw=224&tx=114
&ty=110&sig=103128700
879282556508&sqi=2&p
age=1&tbnh=153&tbnw=
189&start=0&ndsp=15&v
ed=1t:429,r:0,s:0,i:100
Here, the new
Compatible DNA is attached
virus ends are with DNA ligase
joined
9. Still Confused?
• The beginning of this video shows how
Restriction Enzymes work to create
Recombinant DNA:
http://www.youtube.com/watch?v=YdjvUv-1vCI