The Replication factor C (RFC) heteropentamer includes RFC1, RFC2, RFC3, RFC4, and RFC5. The RFC heteropentamer is part of the multiprotein DNA replicase that functions to replicate DNA prior to cell division and repair DNA damage. RFC is the clamp loader ATPase associated with the DNA replicase. As the clamp loader, RFC uses ATP to recruit, open, and close the PCNA ring to link it to DNA for replication and repair. RFC5 is the 36kDa subunit of RFC that forms a core complex with RFC2 and RFC4 and can interact with the C-terminal region of PCNA.