RPA is a heterotrimeric protein complex that binds specifically to single-stranded DNA (ssDNA). It is composed of three subunits, RPA1 (70 kDa), RPA2 (32 kDa), and RPA3 (14 kDa), and plays multiple roles in DNA metabolism. RPA is required for DNA replication initiation, as well as replication elongation. At the onset of DNA replication, RPA is loaded onto chromatin after the binding of Cdc45 to origins. RPA is needed for subsequent loading of DNA polymerase and other replication proteins to initiate DNA replication. After DNA replication begins, RPA moves with replication forks, stabilizing ssDNA and assisting in DNA synthesis. In addition to its replication function, RPA is also known to play essential roles in damage repair and recombination.The 32 kDa 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. Alternate names for RPA32 include replication protein A 32 kDa subunit, RP-A, RF-A, replication f