Approximate details of the spatial configuration of the ordered single-stranded poly(rA) molecule in dilute solution have been obtained in a combined theoretical analysis of base stacking and chain flexibility. Only those regularly repeating structures which fulfill the criterion of conformational flexibility (based upon all available experimental and theoretical evidence of preferred bond rota...

Abstract Hexameric helicases are motor proteins that unwind double-stranded DNA (dsDNA) during replication but how they optimised for strand separation is unclear. Here we present the cryo-EM structure of full-length E1 helicase from papillomavirus, revealing all arms a bound fork and their interactions with helicase. The junction located at entrance to collar ring, sits above AAA + assembly. d...

Single-stranded DNA (ssDNA) is an essential intermediate in various DNA metabolic processes and interacts with a large number of proteins. Due to its flexibility, the conformations of ssDNA in solution can only be described using statistical approaches, such as flexibly jointed or worm-like chain models. However, there is limited data available to assess such models quantitatively, especially f...

The interaction between single-stranded RNAs and liposomes was studied using UV, Fourier Transform Infrared spectroscopy (FTIR) and Circular Dichroism spectroscopy (CD). The effect of the surface characteristics of liposomes, which were composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and modified with cholesterol (Ch) or 1,2-dioleoyl-3-trimethylammonium propane (DOTAP), on t...

P143 is a DNA helicase that tightly binds both double-stranded and single-stranded DNA. DNA-protein complexes rapidly dissociated in the presence of ATP and Mg(2+). This finding suggests that ATP hydrolysis causes a conformational change in P143 which decreases affinity for DNA. This supports the model of an inchworm mechanism of DNA unwinding.

introduction: haemophilia a is the most common inherited x-linked recessive bleeding disorder. the severity of the resultant bleeding diathesis depends on the fviii levels associated with the mutation. analysis of carrier state can be made indirectly by dna linkage analysis or directly by identifying the mutation that leads to the disease. the aim of this study was to identification of the caus...

An essential mechanism for repairing DNA double-strand breaks is homologous recombination (HR). One of its core catalysts is human RAD51 (hRAD51), which assembles as a helical nucleoprotein filament on single-stranded DNA, promoting DNA-strand exchange. Here, we study the interaction of hRAD51 with single-stranded DNA using a single-molecule approach. We show that ATP-bound hRAD51 filaments can...