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Restriction Enzymes Lecture. 2014. What is a restriction enzyme?. An enzyme that cuts DNA at a specific reaction site (sequence). Examples of restriction enzymes. Blunt Ends. “Sticky” Ends. Restriction enzymes are found in bacteria. Restriction enzymes destroy invading bacteriophages
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What is a restriction enzyme? An enzyme that cuts DNA at a specific reaction site (sequence)
Examples of restriction enzymes Blunt Ends “Sticky” Ends
Restriction enzymes are found in bacteria • Restriction enzymes destroy invading bacteriophages • BamHI destroys Bacillus amyloliquefaciens • HindIII destroys Haemophilus influenza
Restriction enzymes in biotechnology Scientists build designer plasmids with specific restriction sites
Restriction enzymes in biotechnology Recombined genes are cloned and expressed
Restriction sites Many restriction sites are often palindromes • Palindromes are the same forwards/backward: • A nut for a jar of tuna • Eva, can I stab bats in a cave
Sticky ends Palindromes result in sticky ends, which form hydrogen bonds easily
BamHI sticky end HindIII sticky end HindIII sticky end BamHI sticky end Laboratory 3: Ligation 3′ 5′ 3′ 5′ 5′ 3′ 5′ 5′ 3′ 3′ 3′ 5′