Double stranded break repair model – Video

Posted: January 27, 2013 at 2:43 am




Double stranded break repair model
For more information, log on to- shomusbiology.weebly.com Download the study materials here- shomusbiology.weebly.com In genetics, the initial processes involved in repair of a double-strand break by synthesis-dependent strand annealing (SDSA) are identical to those in the double Holliday junction model, and have been most extensively studied in yeast species Saccharomyces cerevisiae. Following a double-stranded break, a protein complex (MRX) binds to either end of the break, working with DNA nucleases to carry out resection, resulting in 5 #39; end digest to produce 3 #39; overhangs of single-stranded DNA. These overhangs are then bound to form a nucleoprotein filament, which can then locate DNA sequences similar to one of the 3 #39; overhangs, initiating a single-stranded strand invasion into the DNA duplex containing these sequences. Once strand invasion has occurred, a displacement loop, or D-loop, is formed, at which point either SDSA or a double Holliday junction occurs.[1] Homologous recombination via the SDSA pathway occurs in both mitotic and meiotic cells as an important mechanism of non-crossover recombination, and was first suggested as a model in 1976,[2] acquiring its current name in 1994.[3] As the double Holliday junction model was the first posited in order to explain this phenomenon,[4] various versions of the SDSA model were later proposed to explain heteroduplex DNA configurations that did not match predictions of the double Holliday junction model. Studies in S ...

By: Suman Bhattacharjee

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Double stranded break repair model - Video

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