Replication factor C
The replication factor C, or RFC, is a five-subunit protein complex that is required for DNA replication.
The subunits of this heteropentamer are named Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 in Saccharomyces cerevisiae. RFC is used in eukaryotic replication as a clamp loader, similar to the γ Complex in Escherichia coli. Its role as clamp loader involves catalysing the loading of PCNA onto DNA. It binds to the 3' end of the DNA and uses ATP to open the ring of PCNA so that it can encircle the DNA. ATP hydrolysis causes release of RFC, with concomitant clamp loading onto DNA.
