ICQ7- ch 11 and 10

ICQ7- ch 11 and 10 - S pontaneous mutation DNA polymerase...

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Spontaneous mutation DNA polymerase errors (w/o proofreading- 1 per 10 6 w/-1 per 10 8 ) Base mismatch (point mutation): mismatched base is wobbly and unstable, difficult to add more bases stall Repeat slippage (insertion, deletion): 1 slip per 10 6 – 10 7 repeats, shifted by 2, 4, 6 bps Chemical Hydrolytic cleavage 1. Phosphodiester bonds 2. N-glycosyl bonds- Abasic AP site 1 mutation per 10 5 bp per division: relatively frequent (N glycolylic cleavage) Purine more easily hydrolyzed AP formation sensitizes neighbor to phos. cleavage: deoxyribose ring opens to free aldehyde 3. Bonds linking exocyclic amine groups to bases Water mediated deamination: amine group gets replaced by =O 1 mutation per 10 7 bp per division Cytosine, guanine, adenine uracil, xanthine, hypoxanthine Xanthine: arrests, does not form bp with C or T, causes transition Transition: pyrimidine-purine replaced by pyrimdine-purine Transversion: pyrimdine-purine replaced by purine-pyrimidine Oxidative damage Reactive O could attack but doesn’t 1. Respiratory chain does not release reactive O species
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This note was uploaded on 11/26/2010 for the course BIO 101 taught by Professor Rytasvilgalys during the Spring '09 term at Duke.

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ICQ7- ch 11 and 10 - S pontaneous mutation DNA polymerase...

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