Required for DNA interstrand cross-link repair. This requires cleavage of cross-linked DNA to generate DNA double strand breaks (DSBs). This protein has 5' exonuclease activity on single-stranded and double-stranded DNA, which appears to be necessary for the processing of DNA double strand breaks prior to ligation. Expression is increased by ultraviolet light and agents which induce DNA cross-links such as nitrogen mustard and psoralen. Present with 259 molecules/cell in log phase SD medium. Belongs to the DNA repair metallo-beta-lactamase (DRMBL) family.