Upcoming Colloquia

November 23              
Elio Abbondanzieri (Harvard)
Title: Molecular Gymnastics: The Dynamic Binding Orientations of HIV Reverse, Transcriptase
Abstract:Genetic information is encoded in the nucleic acids DNA and RNA in all organisms. However, it is only through the interaction of proteins with these nucleic acids that this genetic code can be dynamically processed to create life as we know it. Recent advances in fluorescence microscopy have made it possible to probe these crucial interactions at the molecular level in real time. Here, we developed a single-molecule assay to probe the interactions between nucleic acid substrates and a multifunctional enzymatic protein, reverse trancriptase (RT) from HIV. These experiments revealed distinct orientational dynamics of RT on different substrates. RT adopted opposite binding orientations on duplexes containing generic DNA or RNA primers, directing the DNA synthesis or RNA hydrolysis activity, respectively. The relative binding energies of each orientation were governed by the backbone composition at specific nucleotides within the primer. On duplexes containing specific sequences from the HIV genome the enzyme can bind in both orientations, rapidly flipping between the two states without releasing the substrate. On longer duplex substrates, RT was observed to bind at the front and back ends of the duplex and to shuttle between these positions. Shuttling allowed RT to find ends of the nucleic acid rapidly to perform synthesis of new DNA. Shuttling also allowed RT to zip up a frayed duplex displaced by a third nucleic acid strand. These results indicate that the enzymatic activities of RT are determined by its binding orientation on the substrate. Furthermore, by rapidly altering its binding orientation RT is able to catalyze enzymatic reactions more efficiently.

Recent Department News

CDO Networking Day to be held November 18-19, 2009

Efimov States Found

A Celebration of Prof. Sam Fain

Weekly Seminar Schedule

Available Positions in the Department

Archived News Articles

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The Career Development Organization for physicists and astronomers at UW will be hosting it's annual Networking Day on November 18-19, 2009. Please see this announcement flyer and the CDO website for additional information

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First predicted almost 40 years ago,  Efimov States recently have been created in atomic systems.

In 1970, UW Physics Department Lecturer Vitaly Efimov (then at the Ioffe Physico-Technical Institute, St. Petersburg, Russia) predicted a very strange phenomenon, which is now widely known as Efimov effect. If two bosons interact in such a way that a two-body bound state is exactly on the verge of being formed, then in a three-boson system one should observe an infinite number of bound states. All these states are very similar to one another, differing essentially in scale only. If one would be able to change the interaction strength, by making it either weaker or stronger, the number of three-body bound states would become finite. What is even more strange is the fact that this phenomenon can be observed only in a three dimensional system and only in a three-body system. For many years, researchers have sought two-body systems with such finely tuned properties that by adding the third body one would be able to observe the remarkable and very delicate quantum phenomenon of Efimov states. Only recently has Nature been kind enough to provide such a system; atomic physicists have learned how to manipulate the interaction strength between atoms. Several atomic experimental groups now have been able to demonstrate that Efimov states really exist and have the properties predicted long ago by Professor Efimov. A scientific meeting in Rome, Italy,  has been organized and dedicated to the physics of this remarkable quantum phenomenon:  "Efimov States in Molecules and Nuclei: Theoretical Methods and New Experiments," see http://w3.uniroma1.it/efimov2009 .  Professor Efimov will be the guest of honor at this meeting. Congratulations, Professor Efimov!

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Former colleagues and friends of Professor Emeritus Sam Fain, with support from the Department of Physics and the Center for Nanotechnology at the University of Washington have organized a colloquium and two seminars to be given by former graduate students of Sam on Monday, November 16 and Tuesday, November 17, preceded by a reception also on Monday, November 16.

More details and a complete schedule can be found here

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