Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists develop the first atomic view of key genetic processes

26.08.2010
In a landmark study to be published in the journal Nature, scientists have been able to create the first picture of genetic processes that happen inside every cell of our bodies. Using a 3-D visualization method called X-ray crystallography, Song Tan, an associate professor of biochemistry and molecular biology at Penn State University, has built the first-ever image of a protein interacting with the nucleosome -- DNA packed tightly into space-saving bundles organized around a protein core. The research is expected to aid future investigations into diseases such as cancer.

As the genetic blueprint of life, DNA must be deciphered or "read," even when densely packed into nucleosomes. The nucleosome is therefore a key target of genetic processes in a cell and a focus of scientific investigations into how normal and diseased cells work. Previous studies at Penn State and other research institutions led to the discovery of chromatin enzymes -- proteins that act to turn specific genes on or off by binding to the nucleosome.

Since the three-dimensional structure of the nucleosome was determined 13 years ago, scientists have wondered how chromatin enzymes recognize and act on the nucleosome to regulate gene expression and other processes in a cell. "We needed to visualize how these enzymes are able to read such a complicated structure as the nucleosome," Tan said.

To tackle this problem, Ravindra D. Makde, a postdoctoral member of the research team led by Tan, grew molecular crystals of the protein RCC1 (regulator of chromosome condensation, a protein critical for proper separation of chromosomes during cell division) bound to the nucleosome, and used X-ray crystallography to determine the atomic structure of the complex. "Our results showed that the RCC1 protein binds to opposite sides of the nucleosome -- similar to pedals positioned on a tricycle wheel." The structure provides atomic details of how an enzyme can recognize both DNA and components of the protein core of the nucleosome. Unexpectedly, the structure also showed how DNA can stretch as it wraps into a nucleosome. "These findings provide the basis for understanding how RCC1 and other chromatin enzymes interact with DNA as it is packaged into chromatin in our cells," Tan said.

The investigations were performed at the Penn State Center for Eukaryotic Gene Regulation, a multidisciplinary center focused on understanding the molecular basis for how genes are turned off and on in our bodies. "For years, the research community has been at an impasse," said Frank Pugh, Director of the center and the Willaman Professor in Molecular Biology at Penn State. "We were limited to only speculating how cellular proteins might bind the nucleosome. Now, with this structure, we are one step closer to understanding how cells read chromatin to regulate gene expression."

After nearly a decade of working to this goal, Tan and his team are excited to see the intricate interactions between a chromatin protein and the nucleosome. They are, however, even more enthusiastic about future prospects. "Our goal now is to determine the structures of other biologically and medically important chromatin enzymes bound to the nucleosome," said Tan. "We anticipate such studies will explain fundamental genetic processes and provide the basis for new therapeutics against human diseases such as cancer."

In addition to Tan and Makde, other researchers who contributed to this project include Joseph R. England, a Penn State undergraduate when he started this research and currently an MD/Ph.D. student at Temple University, and Hemant P. Yennawar, a senior research associate in the Department of Biochemistry and Molecular Biology at Penn State. This research was funded, in part, by the National Institutes of Health.

[ Katrina Voss ]

CONTACTS
Song Tan: 814-865-3355, sxt30@psu.edu.
Barbara Kennedy (PIO): 814-863-4682, science@psu.edu

Barbara Kennedy | EurekAlert!
Further information:
http://www.psu.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>