SAE2 is a gene in budding yeast, coding for the protein Sae2, which is involved in DNA repair. Sae2 is a part of the homologous recombination process in response to double-strand breaks.^[1] It is best characterized in the yeast model organism Saccharomyces cerevisiae.^[2] Homologous genes in other organisms include Ctp1 in fission yeast, Com1 in plants, and CtIP in higher eukaryotes including humans.^[2]

Sae2 and its homologs have relatively long low-complexity regions in their primary sequences and appear to have large intrinsically unstructured regions. Sae2 likely forms tetramers through coiled-coil sequences.^[2] Proteins of this family are DNA-binding proteins and are involved in DNA end resection and bridging at double-strand breaks.^[3][4] Sae2 has been reported to have endonuclease activity,^[5] though it has no bioinformatically recognizable nuclease sequence and reports of this activity are not consistent in the literature.^[6][2]