As part of the heterotrimeric replication protein A complex (RPA/RP-A), binds and stabilizes single-stranded DNA intermediates, that form during DNA replication or upon DNA stress. It prevents their reannealing and in parallel, recruits and activates different proteins and complexes involved in DNA metabolism. Thereby, it plays an essential role both in DNA replication and the cellular response to DNA damage. Heterotrimer of 51, 28, and 14 kDa chains. Also present in PML nuclear bodies. Redistributes to discrete nuclear foci upon DNA damage (By similarity). Phosphorylated in a cell-cycle-dependent manner (from the S phase until mitosis). Phosphorylated upon DNA damage, which promotes its translocation to nuclear foci (By similarity). Belongs to the replication factor A protein 2 family.