Simulations of the periods, split regularities and mirror symmetries of the glitch pattern of a Si(111) crystal along with the azimuthal angles are presented. The glitch patterns of Si(111) double-crystal monochromators (DCMs) are found to be the superposition of the two sets of glitch patterns from the two crystals. The optimal azimuthal orientation ϕ1,2 = [(2n+1)π]/6 (n = 0, ±1, ±2…) for Si(1...

Fabricated solid-state nanopore chips are used to probe individual single stranded DNA (ssDNA) homopolymers. Based on the analysis of the current blockage caused by DNA translocation through a voltage-biased nanopore, we discovered that the hydrodynamic diameter of ssDNA homopolymer helix is comparable to that of double stranded DNA (dsDNA) helix. This proof-of-principle demonstration shows tha...

When a vortex beam with a spiral phase structure passes through dynamic angular double slits (ADS), the interference pattern changes alternatively between destructive and constructive at the angular bisector of the ADS. This change is due to their phase difference. Based on this property, we experimentally demonstrate a simple method to precisely and efficiently determine the topological charge...

By combining Ce(IV)/EDTA with two pseudo-complementary peptide nucleic acids (pcPNAs), both strands in double-stranded DNA were site-selectively hydrolyzed at the target site. Either plasmid DNA (4361 bp) or its linearized form was used as the substrate. When two pcPNAs invaded into the double-stranded DNA, only the designated portion in each of the two strands was free from Watson-Crick base p...

UNLABELLED Neisseria gonorrhoeae is naturally competent for transformation. The first step of the transformation process is the uptake of DNA from the environment into the cell. This transport step is driven by a powerful molecular machine. Here, we addressed the question whether this machine imports single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) at similar rates. The fluorescence ...

In all organisms, RecA-family recombinases catalyze homologous joint formation in homologous genetic recombination, which is essential for genome stability and diversification. In homologous joint formation, ATP-bound RecA/Rad51-recombinases first bind single-stranded DNA at its primary site and then interact with double-stranded DNA at another site. The underlying reason and the regulatory mec...

Agrobacterium tumefaciens delivers its single-stranded transferred DNA (T-strand) into the host cell nucleus, where it can be converted into double-stranded molecules. Various studies have revealed that double-stranded transfer DNA (T-DNA) intermediates can serve as substrates by as yet uncharacterized integration machinery. Nevertheless, the possibility that T-strands are themselves substrates...

Mechanically interlocked molecules such as rotaxanes and catenanes have potential as components of molecular machinery. Rotaxanes consist of a dumb-bell-shaped molecule encircled by a macrocycle that can move unhindered along the axle, trapped by bulky stoppers. Previously, rotaxanes have been made from a variety of molecules, but not from DNA. Here, we report the design, assembly and character...

Both Rad51 and Rad52 are required for homologous genetic recombination in Saccharomyces cerevisiae. Rad51 promotes heteroduplex joint formation, a general step in homologous recombination. Rad52 facilitates the binding of Rad51 to replication protein A (RPA)-coated single-stranded DNA. The requirement of RPA can be avoided in vitro, if the single-stranded DNA is short. Using short single-strand...