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. 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 CTF18-RFC complex, which consists of CTF18, CTF8, DCC1, RFC2, RFC3, RFC4 and RFC5. Present with 1660 molecules/cell in log phase SD medium. Belongs to the DCC1 family.