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The Mutability and Repair of DNA

The Mutability and Repair of DNA. REPLICATION ERRRORS AND THEIR REPAIR. The nature of mutations. Transitions. Transversions. Some replication errors escape proofreading. Mismatch repair removes errors that escape proofreading. Structure of MutS and DNA

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The Mutability and Repair of DNA

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  1. The Mutability and Repair of DNA REPLICATION ERRRORS AND THEIR REPAIR The nature of mutations Transitions Transversions

  2. Some replication errors escape proofreading

  3. Mismatch repair removes errors that escape proofreading

  4. Structure of MutS and DNA (MutS recognizing mismatches from the distortion they cause)

  5. Dam methylation in E. coli replication fork

  6. Directionality in mismatch repair

  7. DNA DAMAGE DNA undergoes damage spontaneously from hydrolysis and deamination

  8. DNA is damaged by alkylation, oxidation, and radiation

  9. Thymine dimer caused by UV light

  10. Base analogs and intercalating agents that cause mutations in DNA

  11. Ames test for carcinogens

  12. Bruce N. Ames Professor of the Graduate School Division of Biochemistry and Molecular Biology, UC Berkeley

  13. REPAIR OF DNA DAMAGE

  14. Direct reversal of DNA damage

  15. Direct removal of the methyl group from O6 -methylguanine

  16. Base excision repair enzymes remove damaged bases by a base-flipping mechanism

  17. Structure of DNA-glycosylase complex

  18. How is an altered base detected within the context of the double-helix? The recognition of an unusual nucleotide in DNA by base-flipping of glycosylase

  19. Oxo-G:A repair by a fail-safe glycosylase

  20. Nucleotide excision repair enzymes cleave damaged DNA on either side of the lesion

  21. Transcription-coupled DNA repair

  22. Recombination repair DNA breaks by retrieving sequence information from undamaged DNA Double-Strand Breaks are Efficiently Repaired

  23. DSBs in DNA are also repaired by direct joining of broken ends

  24. Translesion DNA synthesis enables replication to proceed across DNA damage

  25. Structures of a translesion polymerase and a typical polymerase

  26. Mutations are linked to cancer

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