Shelterin protein TRF2 modulates telomere structures by promoting dsDNA compaction and T-loop formation. Advancement of our understanding of the mechanism underlying TRF2-mediated DNA compaction requires additional information regarding DNA paths in TRF2-DNA complexes. To uncover the location of DNA inside protein-DNA complexes, we recently developed the Dual-Resonance-frequency-Enhanced Electr...

Insight into crumpling or compaction of one-dimensional objects is important for understanding biopolymer packaging and designing innovative technological devices. By compacting various types of wires in rigid confinements and characterizing the morphology of the resulting crumpled structures, here, we report how friction, plasticity and torsion enhance disorder, leading to a transition from co...

Soil compaction has been recognised as the greatest problem in terms of damage to Australia's soil resource. Compaction by tractor and harvester tyres, related to traf®cking of wet soil, is one source of the problem. In this paper an array of soil properties was measured before and immediately after the application of a known compaction force to a wet Vertisol. A local grain harvester was used ...

The quasistatic behavior of a simple two-dimensional model of a cohesive powder under isotropic loads is investigated by discrete element simulations. We ignore contact plasticity and focus on the effect of geometry and collective rearrangements on the material behavior. The loose packing states, as assembled and characterized in a previous numerical study [Gilabert, Roux, and Castellanos, Phys...

DNA condensation and charge inversion usually occur in solutions of multivalent counterions. In the present study, we show that the organic monovalent ions of tetraphenyl chloride arsenic (Ph4As) can induce DNA compaction and even invert its electrophoretic mobility by single molecular methods. The morphology of condensed DNA was directly observed by atomic force microscopy (AFM) in the presenc...

BACKGROUND Condensin is thought to contribute to large-scale DNA compaction during mitotic chromosome assembly. It remains unknown, however, how the complex reconfigures DNA structure at a mechanistic level. RESULTS We have performed single-molecule DNA nanomanipulation experiments to directly measure in real-time DNA compaction by the Xenopus laevis condensin I complex. Condensin can bind to...

Histone H1 binds to linker DNA between nucleosomes, but the dynamics and biological ramifications of this interaction remain poorly understood. We performed single-molecule experiments using magnetic tweezers to determine the effects of H1 on naked DNA in buffer or during chromatin assembly in Xenopus egg extracts. In buffer, nanomolar concentrations of H1 induce bending and looping of naked DN...

The compaction of granular packings or soils is a collective process which for higher densities becomes increasingly slower reaching glassy behaviour. We present a study of this problem from various points of view, in particular we will represent the evolving force network that percolates through the system by an inverse fiber rupture model.