BIO372H5 Lecture Notes - Lecture 11: Holliday Junction, Chi Site, Heteroduplex

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8 Mar 2014
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Recombination: nicking of dna, single stranded overhang attacks the duplex, strand displacement, further synthesis of dna, intermediate junction: coli recbcd pathway of homologous recombination i. Repair is the initial condition that drove evolution. Under conditions of high magnesium, the activity is higher. Acts as endonuclease, and degrades and unwinds dna, until it reaches a chi site (a consensus). 30 bp is not enough, if over this, the d-loop will form (displacement-formation), after which reca is released. Atp is needed to unload (no atp no recombination!) Holliday junction - the polynucleotide switch between duplex. They are heteroduplex which contain potential mismatches (contain both blue and red from different parents) Holliday junction migration - a diffusion process, it is neutral, slow process, less enzymes are. Holliday junction migration - a diffusion process, it is neutral, slow process, less enzymes are involved. G and h resolutions are two possible resolutions - equally likely to happen.