microbial genetics micr340 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Microbial Genetics (Micr340) PowerPoint Presentation
Download Presentation
Microbial Genetics (Micr340)

Loading in 2 Seconds...

  share
play fullscreen
1 / 19
cheri

Microbial Genetics (Micr340) - PowerPoint PPT Presentation

91 Views
Download Presentation
Microbial Genetics (Micr340)
An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Microbial Genetics (Micr340) Lecture 14 DNA Repair and Mutagenesis

  2. Definitions • Lesion: chemical damage in DNA • Mutagens: chemical compounds that cause lesions in DNA which can kill cells and can also increase frequency of mutations in DNA

  3. Evidence for DNA repair

  4. Specific Repair Pathways • Repair of deaminated bases • Damage due to reactive oxygen • Alkylation of DNA and repair • Pyrimidine dimer repair

  5. Base Deamination by nitrous acid

  6. Spontaneous Base Deamination

  7. Repair of altered bases by DNA glycosylases

  8. Damage due to reactive oxygen

  9. Mechanism of avoiding GO

  10. AlkylationOf guanine

  11. Repair of alkylated DNA • Specific N-glycosylases • Methyltransferases

  12. PyrimidineDimer Formation

  13. Photoreactivation

  14. General Repair Mechanisms • Methyl-directed mismatch repair system • Nucleotide excision repair • SOS inducible repair

  15. A model for methylDirected mismatch repair

  16. A model for nucleotide excision repair

  17. SOS response

  18. SOS response

  19. Regulation of SOS mutagenesis in E. coli