Component of the replication protein A complex (RPA) required for DNA recombination, repair and replication. The activity of RPA is mediated by single-stranded DNA binding and protein interactions. Probably involved in repair of double-strand DNA breaks (DSBs) induced by genotoxic stresses (By similarity). Heterotrimer of RPA1, RPA2 and RPA3 (canonical replication protein A complex) (By similarity). Interacts with RPA2C. Belongs to the replication factor A protein 1 family.