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Figure 4.
Figure 4. Averaged Electron Microscopic Image of the
RuvA-RuvB-Holliday Junction Ternary Complex and the
Corresponding Functional Atomic ModelThe IMAGIC program package
(van Heel et al., 1996) was used to cluster particle images and
to obtain class averages. The hypothetical model was constructed
by fitting the RuvA octameric core structure (yellow) and the
RuvB hexamer models (blue) into the averaged images, referring
to the hexameric oligomerization of the HslU protein similar to
RuvB (Sousa et al., 2000). One pair of subunits related in
each hexameric ring by the central 2-fold axis was replaced by
the two domain III (orange)-RuvB (magenta) complexes (see text).
Averaged electron microscopic images correspond to two
orthogonal views of the ternary complex. The 858 original
images were grouped into three major classes of averaged images,
and only two of them, (A) and (B), averaged from 171 and 370
electron microscopic images, are shown here. Note the good
coincidence of the images with the side (A) and end views (B) of
the RuvA octameric core structure. The resolutions of the
averaged images of (A) and (B) were estimated at 34 and 31
Å, respectively, from differential phase residuals. The
scale bar represents 100 Å.
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