Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Structure of new DNA enzyme family member found

04.11.2004


Cornell University researchers, who are trying to understand how proteins evolve and function by looking at their structural features, have uncovered the crystal structure of a protein involved in making the building blocks of DNA correctly.



The protein is AIRs kinase, and to the researchers’ surprise, its shape is similar to other members of the riboside kinase family, proteins that are important in making DNA and RNA, the molecules that make up genes. As a result, the research group now has nine members of the riboside kinase family that are thought to have evolved from a common protein ancestor. Writing in a recent issue of the journal Structure , Steven Ealick, professor of chemistry and chemical biology, and his graduate student Yan Zhang report that revealing the structure of AIRs kinase is another step in deciphering what proteins look like, a major goal of the National Institutes of Health, which funds the Ealick research group’s work.

"Often, two proteins with the same function have no sequence similarity," says Ealick, whose research group works with crystallized proteins, the building blocks of all living organisms, and has solved 50 protein structures over the past 20 years. "From knowing the genetic sequence alone, we wouldn’t necessarily guess that two proteins play a similar role in an organism."


Zhang took just two months of "trial and error" -- an unusually short time -- to get the AIRs kinase protein to crystallize. Then, using the Northeastern Collaborative Access Team (NE-CAT) beamline at the Advanced Photon Source at Argonne National Laboratory and the Cornell High Energy Synchrotron Source, two of only five sources of high-energy X-ray beams, she obtained the protein’s "optical transform," the intermediate stage between the crystal and the ultimate model of the structure.

Ealick explains, "Optical transform is what happens when you scatter light from a microscope onto a specimen, but until you have an objective lens that refocuses that light you can’t actually see an image." Structural protein chemists don’t have the equivalent of a microscope’s objective lens, so they "refocus" the image using computers.When the Ealick group compared the AIRs kinase protein to other known protein structures, they found that the shape was similar to other members of riboside kinase protein family. Ealick explains that even though the family members don’t have appreciable sequence similarity, they all contain three invariable amino acids. The similar shapes of the proteins position these three important pieces at the right place in the protein, and as a result, they all have a similar function -- the addition of a phosphate group to a DNA or RNA precursor.

"When we saw how very similar these proteins look, we began to ask whether there might be a common ancestor or whether proteins might evolve using similar kinds of rules that whole organisms use to evolve," Ealick reasons. In fact, his group is finding numerous examples of this.

Says Ealick, "I view this like the drawing you often see in textbooks on human evolution that first shows a primitive chimpanzee, and then you go through various morphological changes until you finally get to modern man. You can see the same sort of trends in the evolution of protein shapes."

The primitive protein began as a general kinase, playing lots of roles in the cell, he says. Eventually, it evolved and diverged into a group of different proteins, each of which could focus on a specialized task.

Ealick’s group now hopes to design a broad specificity riboside kinase as a laboratory tool for testing anticancer drugs and other pharmaceuticals. The group also is working to get the structure of other riboside kinase family members in order to be able to predict the proteins’ function.

David Brand | EurekAlert!
Further information:
http://www.cornell.edu

More articles from Life Sciences:

nachricht Bare bones: Making bones transparent
27.04.2017 | California Institute of Technology

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

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...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

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...

Im Focus: Deep inside Galaxy M87

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...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

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...

Im Focus: Microprocessors based on a layer of just three atoms

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>