1. DNA Mutations and Repair
Chapter 17

2. Chernobyl, April 26th, 1986
Equal to medium nuclear bomb

3. Radiation
(Techa River)
Hiroshima (Aug. 6th, 1945)

4. DNA Repair: general characteristics
Double stranded DNA
Redundancy of pathways

5. Types of DNA repair Mismatch repair Direct Repair Base-Excision Repair
Nucleotide Excision Repair

6. Mismatch repair
Mut H
Recognize GATC hemi-methylation
Mut S
Mut L

7. A closer look at mismatch repair

8. DIRECT REVERSAL REPAIR
Direct Repair

9. BASE EXCISION REPAIR

10. BASE EXCISION REPAIR

11. Nucleotide Excision Repair

12. Xeroderma pigmentosum
UV light damage
Autosomal recessive
Error in DNA excision-repair enzymes

13. Hereditary Non-Polyposis Colon Cancer
HNPCC
15% of all colon cancers

14. Li-Fraumeni
P-53 mutation