Component of ATP-dependent clamp loader (RFC and RFC-like) complexes for DNA clamps, such as the POL30/PCNA homotrimer and the checkpoint clamp DDC1:MEC3:RAD17 complex. During a clamp loading circle, the RFC:clamp complex binds to DNA and the recognition of the double-stranded/single-stranded junction stimulates ATP hydrolysis by RFC. The complex presumably provides bipartite ATP sites in which one subunit supplies a catalytic site for hydrolysis of ATP bound to the neighboring subunit. Dissociation of RFC from the clamp leaves the clamp encircling DNA. Component of the replication factor C (RFC or activator 1) complex which loads POL30/PCNA and acts during elongation of primed DNA templates by DNA polymerase delta and epsilon. RFC has an essential but redundant activity in sister chromatid cohesion establishment. Component of the RFC-like complex CTF18-RFC which is required for efficient establishment of chromosome cohesion during S-phase and may load or unload POL30/PCNA. Component of the RFC-like RAD24-RFC complex which loads the checkpoint clamp DDC1:MEC3:RAD17 complex and is involved in DNA repair pathways. Component of the RFC-like ELG1-RFC complex which appears to have a role in DNA replication, replication fork re-start, recombination and repair. Replication factor C (RFC) is a heteropentamer of subunits RFC1, RFC2, RFC3, RFC4 and RFC5 and forms a complex with POL30/PCNA in the presence of ATP. Component of the RAD24-RFC complex which consists of RAD24, RFC2, RFC3, RFC4 and RFC5 and associates with the checkpoint clamp DDC1:MEC3:RAD17 complex. Component of the ELG1-RFC complex which consists of ELG1, RFC2, RFC3, RFC4 and RFC5. Component of the CTF18-RFC complex, which consists of CTF18, CTF8, DCC1, RFC2, RFC3, RFC4 and RFC5. RFC5 interacts with ECO1. Present with 5040 molecules/cell in log phase SD medium. Belongs to the activator 1 small subunits family.