Schematic illustrations of the molecular mechanisms of chromatin compaction by histone H1 and Topo II
Taken from "Topoisomerase II, scaffold component, promotes chromatin compaction in a linker-histone H1-dependent manner"
Nucleic Acids Research 2007;35(8):2787-2799.
Published online 11 Apr 2007
© 2007 The Author(s)() Stepwise packing of reconstituted chromatin. First, DNA forms a nucleosomal fiber with core histones, and histone H1 induces the formation of 30-nm fibers. Second, Topo II induces compaction when the 30-nm fiber is formed in the presence of histone H1. () Molecular mechanism of Topo II-induced chromatin compaction. Topo II clamping of two DNA strands induces a small amount of aggregation of beads-on-a-string nucleosomal fibers but promotes large-scale aggregation of 30-nm fibers.