1 / 10

DNA Synthesis

DNA Synthesis. •Eukaryotes. •DNA unwinds at a replication origin •Two replication forks form •Bidirectional synthesis of DNA •Much more DNA; complexed with proteins. •Eukaryotes have much more DNA. •Yeast 4X that of E. coli •Drosophila 100X that of E. coli. •Solution:

heller
Download Presentation

DNA Synthesis

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DNA Synthesis •Eukaryotes •DNA unwinds at a replication origin •Two replication forks form •Bidirectional synthesis of DNA •Much more DNA; complexed with proteins •Eukaryotes have much more DNA •Yeast 4X that of E. coli •Drosophila 100X that of E. coli •Solution: Multiple replication origins •Yeast 250-400 replicons •Mammalian cells up to 25,000

  2. DNA Synthesis in Eukaryotes Pre-initiation replication complex: ORC Cdt1 Cdc6 MCM

  3. Comparison of some replication components

  4. A Problem and a Solution

  5. Telomere Formation

  6. The Damage and Repair of DNA Two main types of DNA damage: *point mutations *structural changes The molecular basis of point mutations 1. Base substitution (mismatches) transition transversion 2. Tautomeric shift

  7. Gene Mutation The molecular basis of point mutations 3. Base analogs and chemical mutagens

  8. DNA Damage The molecular basis of structural damage 1. Hydrolytic damage Deamination N-glycosidic bond – very weak and easily broken Depurination Deamination

  9. DNA Damage The molecular basis of structural damage 2. Alkylation

  10. DNA Damage The molecular basis of structural damage 3. Oxidation and Radiation

More Related