5'->3' double-stranded DNA exonuclease that could act in a pathway that corrects mismatched base pairs. Binds 2 magnesium ions per subunit. They probably participate in the reaction catalyzed by the enzyme. May bind an additional third magnesium ion after substrate binding. Monomer. By meiosis. Belongs to the XPG/RAD2 endonuclease family. EXO1 subfamily.