University of Illinois at Chicago physics professor Anjum Ansari hopes to find some answers, supported by a new five-year, $1.14 million National Science Foundation grant.
Ansari and her UIC laboratory team are studying two classes of DNA-bending proteins. One is a "damage recognition" protein that recognizes a mismatched base-pair, binds to that site, and then signals for helper proteins to gather and aid in the repair. The other protein is an enzyme that targets invader DNA, cutting it apart.
Ansari is collaborating with other researchers at UIC, University of Pittsburgh, Wesleyan University and Arizona State University to study different aspects of these proteins.
Ansari's lab is one of only a few equipped to monitor the dynamics of DNA bending in complex with these proteins on timescales ranging from several milliseconds down to as fast hundreds of nanoseconds -- or less than one-millionth of a second.
The instruments in her lab are designed to look at macromolecules as they change their shapes within this time window -- "which is precisely the time window in which proteins recognize their specific binding sites," she said.
Researchers have made measurements at the longer timescales on which proteins diffuse along DNA in search of target sites Ansari said, "but not much is known about the timescale of the recognition process, for virtually any protein."
Her lab's experiments "are designed to make time-resolved measurements of how a protein, when it reaches its target site, transforms the DNA from a conformation in which it is straight to one which is kinked and bent," Ansari said, and to "learn about the recognition mechanism by watching the dynamics -- or time scales -- on which this happens."
Many other biophysical questions about this protein-DNA interaction will be investigated by the team, including the presence of subtle kinks in DNA structure at the damage sites in the absence of a bound protein.
"Clearly, the kinked conformation of the DNA facilitates the [protein's] recognition that something is wrong at the site," Ansari said. "The question we're addressing is, 'Is it the protein that bends and kinks the DNA when it reaches that site?' Or does the DNA, on its own, have a propensity to adopt these locally bent conformations because there's a mismatch -- and the protein, when it is moving along on the DNA, recognizes that something is not right at certain spots?"
DNA gets damaged in various ways -- sometimes during replication, sometimes by ultraviolet radiation, and sometimes through more subtle cellular processes. Damaged DNA can lead to serious diseases, so a better understanding of how proteins make repairs can help when designing new and better therapies.
Ansari will incorporate some aspects of her research in undergraduate physics labs that she plans to develop as part of a new biophysics curriculum at UIC.
Paul Francuch | Newswise Science News
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences