Functions in cell replication and proliferation. May be involved in chromatin assembly and remodeling. Plays a role in the negative control of pathogenesis-related gene expression and systemic acquired resistance (SAR). Heterotetramer of subunits RFC2, RFC3, RFC4 and RFC5 that can form a complex with RFC1. By salicylic acid (SA). Moderately dwarfed plants with small organs due to reduced cell proliferation rate. Enhanced resistance to pathogens. Belongs to the activator 1 small subunits family.