Figure 3.

The RAP1 site in miniARS317 contributed to plasmid distribution but not intrinsic replication efficiency. (A) The organization and positions of key elements within silencer ARS317 are indicated at the top by black lines. The eight thicker black lines immediately below these represent the miniARS317 fragment tested in direct ARS (autonomously replicating sequence) assays. Low #1–5 indicate fragments with low competitive fitness in the miniARS experiment described in Figure 1. Thus, fragment #3 lacked a portion of the putative FKH* (forkhead) site (putative B3 element), while fragment #4 contained this region of miniARS317 but lacked the RAP1 (Rap1 protein binding site) site. Fragments #6–8 showed high competitive fitness in the miniARS experiment. Only fragment #6 contains the silencer ABF1 (ARS-binding Factor 1) site (B) Each of the fragments represented in (A) was tested for ARS function in a centromere-containing plasmid (+centromere, black) or in an analogous plasmid lacking a centromere (–centromere, gray). Standard ARS assays were performed as described and the mean plasmid loss rate per generation (PLR) and associated standard error is indicated in the bar graph for a minimum of three independent experiments. ORC, origin recognition complex.