Featured Research

from universities, journals, and other organizations

First 3-D atomic view of key genetic processes

Date:
August 27, 2010
Source:
Penn State
Summary:
Scientists have created the first 3-D picture of genetic processes that happen inside every cell of our bodies. The picture is the first-ever image of a protein interacting with DNA in its tightly packed "nucleosome" form. The research, which reveals new information about genetic processes, is expected to aid future investigations into diseases such as cancer.

Scientists at Penn State University have created the first 3-D picture of genetic processes that happen inside every cell of our bodies. The picture is the first-ever image of a protein interacting with DNA in its tightly packed "nucleosome" form. The research, which reveals new information about genetic processes, is expected to aid future investigations into diseases such as cancer. This 2-D image illustrates the RCC1 chromatin protein interacting with the nucleosome.
Credit: Song Tan laboratory, Penn State University

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.


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Journal Reference:

  1. Makde et al. Structure of RCC1 chromatin factor bound to the nucleosome core particle. Nature, 2010; DOI: 10.1038/nature09321

Cite This Page:

Penn State. "First 3-D atomic view of key genetic processes." ScienceDaily. ScienceDaily, 27 August 2010. <www.sciencedaily.com/releases/2010/08/100825131453.htm>.
Penn State. (2010, August 27). First 3-D atomic view of key genetic processes. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2010/08/100825131453.htm
Penn State. "First 3-D atomic view of key genetic processes." ScienceDaily. www.sciencedaily.com/releases/2010/08/100825131453.htm (accessed April 24, 2014).

Share This



More Matter & Energy News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Next Stop America for France's TGV?

Next Stop America for France's TGV?

Reuters - Business Video Online (Apr. 24, 2014) General Electric keeps quiet on reports it's in talks to buy French turbine and train maker Alstom. Ivor Bennett reports on what could be an embarrassing rumour for the French government, with business-friendly reforms proving a hard sell. Video provided by Reuters
Powered by NewsLook.com
Raw: Obama Plays Soccer With Japanese Robot

Raw: Obama Plays Soccer With Japanese Robot

AP (Apr. 24, 2014) President Obama briefly played soccer with a robot during his visit to Japan on Thursday. The President has been emphasizing technology along with security concerns during his visit. (April 24) Video provided by AP
Powered by NewsLook.com
Obama Encourages Japanese Student-Scientists

Obama Encourages Japanese Student-Scientists

AP (Apr. 24, 2014) President Obama spoke with student innovators in Japan and urged them to take part in increased opportunities for student exchanges with the US. (April 24) Video provided by AP
Powered by NewsLook.com
UN Joint Mission Starts Removing Landmines in Cyprus

UN Joint Mission Starts Removing Landmines in Cyprus

AFP (Apr. 23, 2014) The UN mission in Cyprus (UNFICYP) led a mine clearance demonstration on Wednesday in the UN-controlled buffer zone where demining operations are being conducted near the Cypriot village of Mammari. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins