(A) Composite cryo-EM density map showing extra density, only visible in the original Ctf19c map, which likely belongs to Mcm21-N. The image was created by combining the high-resolution Ctf3c map (blue and gray) with the displayed yellow density from the Ctf19c map (EMDB-0523). The inset shows the position of the map in the context of the full Ctf19c model. (B) Cryo-EM density showing the interaction between Ctf3 and Iml3. The top panel shows density determined for the interface in the context of the full Ctf19c. The bottom panel shows a composite model; Iml3 coordinates refined into the Ctf19c cryo-EM map are green, and Ctf3 coordinates refined into the current density map are blue. (C) The indicated S. cerevisiae strains (CTF3 – CTF3-3FLAG: SMH690, SMH691, SMH692; iml3Δ: SMH91; ctf3-SDD – ctf3-SDD-3FLAG: SMH693, SMH694, SMH695) expressing Mcm22-GFP and Spc110-mCherry were imaged during asynchronous division. Coincidence frequencies of Mcm22-GFP foci with Spc110-mCherry foci are plotted (error bars –±SD for frequency measurements from three independent cultures; * – p<0.05; ** – p<0.01, Student’s t-test, two tails, unequal variance).