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The paper
Y. Yu et al., “Dna2 nuclease deficiency results in large and complex DNA insertions at chromosomal breaks,” Nature, 564:287–90, 2018.
Few things are as dangerous for a cell as a DNA double-strand break. If both strands of the double helix are severed and left unrepaired, the cell could die at the next round of mitosis.
To protect against such a fate, a suite of DNA-repairing proteins is on standby for when breaks occur. One of them is the evolutionarily conserved enzyme Dna2, which helps prepare broken DNA strands for repair by other proteins and also degrades excess pieces of DNA produced during replication.
To better understand the enzyme’s role, Grzegorz Ira, a geneticist at Baylor College of Medicine, and colleagues recently investigated the consequences of deleting Dna2 in yeast. The deletion alone would be fatal to the cells, likely because the bits of DNA ...
