FIG. 2.

Multiple pathways of replication fork assembly at recombination intermediates. One possible set of pathways, based on the genetic data discussed in the text, involves the replication restart primosomal proteins and Rep during replication fork assembly at recombination intermediates. Each column denotes one possible pathway. The steps separated by vertical arrows in each column represent the order of action of particular proteins during assembly of the restart primosome. This order of assembly is based on biochemical data discussed in the text. The bifurcation in the PriA-dependent pathway indicates that PriA can interact with either PriB or PriC (and Rep?). Question marks indicate that the action of this protein in the pathway is unclear. Regardless of which proteins are present on the recombination intermediate as a final protein-DNA complex, the object of each pathway is to place DnaB in position on single-stranded DNA so that a new replication fork can form.