Repairing a double-strand chromosome break by homologous recombination: revisiting Robin Holliday's model.

摘要: Since the pioneering model for homologous recombination proposed by Robin Holliday in 1964, there has been great progress understanding how occurs at a molecular level. In budding yeast Saccharomyces cerevisiae, one can follow physically monitoring DNA after synchronous induction of double-strand break (DSB) both wild-type and mutant cells. A particularly well-studied system switching mating-type (MAT) genes, where DSB be induced synchronously expression site-specific HO endonuclease. Similar studies performed meiotic cells, DSBs are created Spo11 nuclease. There appear to least two competing mechanisms recombination: synthesis-dependent strand annealing pathway leading noncrossovers two-end invasion mechanism formation resolution junctions (HJs), crossovers. The establishment modified replication fork during repair links gene conversion another important process, break-induced replication. Despite recent revelations, almost 40 years Holliday's was published, essential ideas he heteroduplex formation, HJs, mismatch repair, remain basis our thinking.