Figure 1. Assembly of four guanine (G) nucleobases into a quadruplex. The potassium ion in the center stabilizes the structure by bonding to the oxygen atoms on each guanine.
Figure 2. Chemical structures of DNA, RNA and PNA.
A team of investigators at Carnegie Mellon University has formed the first hybrid quadruplex of peptide nucleic acids, or PNAs, with DNA, the genetic code. This result opens new opportunities to study the activity of genetic regions occupied by recently described quadruplex DNA structures, as well as providing a new compound that could be used as a biosensor or to block gene activity associated with diseases such as cancer. The research results, published online, will appear in a forthcoming issue of the Journal of the American Chemical Society.
"PNA2-DNA2 hybrid quadruplexes are extremely stable, suggesting that if we use PNAs to bind with DNA quadruplexes that regulate gene expression, we could prevent disease processes in which these DNA quadruplexes appear to play a role," says Bruce Armitage, Ph.D., associate professor of chemistry at Carnegie Mellon. "PNAs also could be converted into biosensors by coupling them with fluorescent tags that would allow the PNA to report the presence of a successful hybridization to quadruplex-forming sequences either in the genome or in messenger RNA molecules."
"In addition to a new high-affinity DNA recognition mechanism and expanding the scope of molecular recognition by PNA, the PNA2-DNA2 hybrid quadruplex is the first example of homologous hybridization," adds Armitage.
Lauren Ward | EurekAlert!
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy