Restriction enzymes Flashcards
Certain enzymes found naturally can break the sugar phosphate backbone of DNA. How are they called?
Endonucleases
What are restriction enzymes?
These are endonuclease that recognize specific base sequences and cut the DNA backbone at that site
Where do restriction enzymes come from and how are they named?
They come from bacteria and are named after the bacteria from which they were isolated
Give some examples of restriction enzymes and their bacteria
EcoRI from E. coli
HindIII from H. influenzae
Regions of DNA that contain specific base sequences recognized by restriction enzymes are called
Restriction sites
What does it mean when restriction sites are said to be palindromic?
They read the same sequence 5’ to 3’ on both strands of DNA
Some restriction enzymes cut with a staggered separation at the restriction site leaving overhangs called
Sticky ends
Other enzymes cut the both strands at the same point producing
Blunt ends
Where are restriction sites found?
Naturally all through the DNA sequence
How is restriction map created?
By cutting DNA with several restriction enzymes together and separately.
What is RFLP used for?
To detect mutations that alter restriction sites.
How is RFLP carried out?
A DNA sequence region is amplified by PCR and followed by cutting of DNA with an appropriate restriction enzyme followed by gel electrophoresis separation.
How is fragment size determined?
By distance between the restriction sites.
Mutations can either
create or destroy restriction sites
List two commonly occurring mutations RFLP is used to detect
- Factor V Leiden disease (clotting disease)
- Hereditary hemochromoatosis (iron overload)
