May be required for DNA interstrand cross-link repair. Also required for checkpoint mediated cell cycle arrest in early prophase in response to mitotic spindle poisons. a beta-lactam + H2O = a substituted beta-amino acid Binds constitutively to TP53BP1. Binds CDC27, which is itself a component of the anaphase promoting complex (APC). Binds PIAS1 (By similarity). In some cells it may be found in typically 1 or 2 discrete nuclear aggregates of unknown function which also contain TP53BP1. Also found in multiple discrete nuclear foci which increase in number following treatment with ionizing radiation or interstrand cross-linking agents. These foci overlap with those formed by the MRN complex (composed of MRE11, RAD50 and NBN) and BRCA1 (By similarity). Belongs to the DNA repair metallo-beta-lactamase (DRMBL) family. Intron retention.