1. 22 September, 2006 Chapter 9 Mutation and Repair

2. Overview DNA is replicated with high fidelity, but errors do occur. Errors during replication may be misincorporation or slippage. Errors that are not repaired by proofreading may be repaired my the mismatch repair systems. Mismatch repair systems rely on methylation to determine which base is correct. In addition to replication errors, DNA can be damaged by radiation, chemicals, or spontaneous reactions. DNA repair systems are specialized according to the type of damage they address.

3. Transitions and Transversions

4. Ratification of unrepaired errors

5. Mismatch Repair

7. Dam Methylation in E. coli

8. Exonuclease activity exposes lesion

9. DNA Damage

10. Base Analogs and Intercalators

11. Photoreactivation

12. O6-Me-G repair

13. Base excision repair

15. Fail-safe systems

16. Excision Repair

17. Excision repair may be coupled to transcription.

18. Translesion Synthesis

19. Ames Test