FIGURE 4.

Mcm4-Mcm7 complex is ring-shaped. A, Mcm4 was incubated with equimolar Mcm7 in the absence and presence of glutaraldehyde as described under “Experimental Procedures.” The Mcm4-Mcm7 complex was then diluted and analyzed by negative stain electron microscopy. The boxed area is enlarged to show detail. For comparison, an equimolar mixture of Mcm4/Mcm6/Mcm7 was diluted and analyzed by negative stain electron microscopy using the same procedures. B, selected Mcm4/Mcm7 rings from experiments described in A were averaged using Scion Imaging software. C, outer diameters of 100 ring-shaped Mcm4/Mcm7 particles from experiments described in A were measured and plotted.