FIG. 5.

Replication of plasmid RSF1010 by the strand displacement mechanism. (a) Origin of replication and related regions. The interaction sites of RepB (inverted repeat [convergent arrows]) and of RepC (iterons [boxed arrows]) are indicated. GC- and AT-rich regions are also depicted. (b) Model for initiation of replication by the strand displacement mechanism in plasmid RSF1010 (266). Replication occurs with opposite polarities from two origins (ssiA and ssiB), which are independently used. Interactions between the plasmid-encoded proteins RepC and RepA are indicated. Priming is catalyzed by RepB′ (not shown). Thin lines indicate newly synthesized DNA, with the direction of synthesis indicated by arrowheads. See the text for details.