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 RPA2A. Expressed in root tips, roots, shoot apical meristem (SAM) and young leaves, and at lower levels in mature leaves, flag leaves and ears. Repressed by sucrose starvation. Belongs to the replication factor A protein 1 family.