Replication protein A (RPA) is a multisubunit complex that carries out DNA mismatch repair (MMR) in association with MSH2 (a subunit of human MutS heterodimers), MLH1 (a subunit of human MutL heterodimers), PCNA, and DNA polymerase-delta. RPA is composed of a heterotrimer that includes subunits of 70 kDa (RPA1), 32kDa (RPA2), and 14kDa (RPA3). RPA2, the 32kDa subunit, is phosphorylated by the cdc2 family of kinases when cells enter S-phase and in response to DNA damage by ATM, ATR, and DNA-PK.