Restriction Endonucleases David Peterson

Structure of DNA and RNA

Information Flow in Cells DNA RNA Protein Transcription Translation

Amino acids combine to make peptides and proteins

Catalyze reactions Most are proteins Enzymes Catalyze reactions Most are proteins

Restriction endonucleases cut DNA at specific sites X174 DNA HaeIII HinfI

Restriction Enzymes Aid in DNA Cloning

Palindromes Madam, I’m Adam. Gary knits a stinky rag. Harass sensuousness, Sarah. Go hang a salami, I’m a lasagna hog.

Most Restriction Enzymes Recognize Palindromes 5'-GATATC-3' 3'-CTATAG-5'

EcoRV Bound to DNA www.pdb.org 1AZ0

Phage l 48,512 bp dsDNA virus that grows on E. coli. Life cycle ~ 30 min at 37°C typical burst ~ 100-300 particles

Bacteriophage infection: 1 → 300 → 10,000 → 3,000,000 → 109 Phage DNA Bacterium 30 min Typical phage infection cycle: 1. Phage DNA penetrates bacterial envelope 2. Bacterial DNA is disrupted & phage DNA is replicated 3. Phage structural proteins are synthesized 4. Heads, tails, fibers made and assembled into particles 5. Cell lysis, release of ~ 100 – 300 phage particles

Bacteriophages Make Plaques

Nobel Prize in Physiology or Medicine 1978 Werner Arber Dan Nathans and Hamilton Smith Nobel Prize in Physiology or Medicine 1978