DnaC

dnaC is a prokaryotic loading factor found in Escherichia coli that complexes with the C-terminus of helicase dnaB during the initial stages of prokaryotic DNA replication, loading dnaB onto DNA and inhibiting it from unwinding double stranded DNA (dsDNA) at a replication fork. Both dnaB and dnaC associate near the dnaA bound origin for each of the single stranded DNA molecules (ssDNA). Since DNA is antiparallel, one dnaB-dnaC complex is oriented in the opposite direction to the other dnaB-dnaC complex. After the assembly of dnaG, a primase, onto the N-terminus of dnaB, dnaC is released and dnaB will be allowed to begin unwinding dsDNA to make room for DNA polymerase to begin synthesizing the daughter strands.

This interaction of dnaC with dnaB requires the hydrolysis of ATP.