XB-IMG-123796
Xenbase Image ID: 123796
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Figure 4. Helical phasing is required for the condensation of overlapping dinucleosomesStructural models of dinucleosomes on the (-44bp) construct in the unfolded (left) and folded (right) states (a).. The exposed inner dimer on the complete nucleosome is highlighted red. Other histone proteins are shown in blue and DNA in yellow. b, A plot of the root mean square deviation (RMSD) of phosphorus atoms as a function of the overlap length for partial superimposition of two copies of the DNA superhelix in 1KX5. For a chosen overlap length n the last n base pairs in the first copy were superimposed with the first n base pairs in the second copy. The helical periodicity suggests that formation of compact structures is likely to require helical phasing. c-e, AFM imaging of dinucleosomes with overlaps lengths of -44, -49 and -54 bp following fixation in 5 mM Mg2+. Formation of compact particles is observed for the (-44bp) and (-54bp) constructs that coincide with minima in a, unfolded particles predominate for the -49bp construct. Image published in: Engeholm M et al. (2009) Image downloaded from an Open Access article in PubMed Central. Image reproduced on Xenbase with permission of the publisher and the copyright holder. Larger Image Printer Friendly View |