Figure 4

Mutants that diminish the Sld3–Esa1 interaction exhibit weaker anti-silencing effects and higher plasmid loss of HMLα origins. (A) Isolation of Sld3 mutants with diminished interactions with Esa1. Y2H analysis was performed with the plasmids encoding the indicated proteins. (B) HMLα::URA3 cells expressing Sld3 wild-type or Sld3^Esa1(−) mutant proteins with Sld7 and Cdc45 were serially diluted, spotted, and grown on the indicated plates. Strains used were YST1862 (Δsir2), YST1861 (Δsir1), UCC3515 (−), YST2827 (+GALp vector), YST2828 (Sld3 (wt)), YST2832 (Sld3^Esa1(−)-2), YST2834 (Sld3^Esa1(−)-1), and YST2831 (Sld3^Esa1(−)-3). (C) Plasmid loss assay was performed in the sld3^Esa1(−)-3 (YST2870) and esa1^Sld3(−)-3 (YST2741) strains (Wt: YST2843). The average of three independent results is shown. Error bars: SD. Statistical significance in the differences was tested by the Student's t-test. **P < 0.01, *0.01 < P < 0.05, and n.s. (not significant): P > 0.05. Actual P-values are also shown.