Featured Research

from universities, journals, and other organizations

Newly Revealed Viral Structure Suggests A Continuum In The Evolution Of Viruses

Date:
September 26, 2002
Source:
The Wistar Institute
Summary:
An international team of scientists led by researchers at The Wistar Institute has combined two different imaging techniques to uncover the molecular-level framework of a common bacteriophage, a virus that infects bacteria. The results, reported in the October issue of Nature Structural Biology, suggest that viruses developed a continuum of progressively more complex architectural strategies to cope with their increasing size as they evolved.

PHILADELPHIA - An international team of scientists led by researchers at The Wistar Institute has combined two different imaging techniques to uncover the molecular-level framework of a common bacteriophage, a virus that infects bacteria. The results, reported in the October issue of Nature Structural Biology, suggest that viruses developed a continuum of progressively more complex architectural strategies to cope with their increasing size as they evolved. An image from the study is featured on the journal's cover.

The new findings may open a novel approach to developing therapies for certain difficult-to-treat infections. The bacteriophage studied, called PRD1, infects antibiotic-resistant strains of E. coli bacteria, including strains responsible for tens of thousands of cases of food poisoning in the United States each year. The intimate knowledge of PRD1's structure provided by the current study might help scientists develop a treatment for E. coli infections involving PRD1.

The structural details show that the bacteriophage has similarities to viruses smaller than itself, simple plant and animal viruses whose outer coats are formed from proteins held together by linked "arms." In addition, however, it also uses small "glue" proteins to cement larger proteins together. This feature makes it more like the human adenoviruses, larger and more complex viruses that infect the respiratory tract and cause other diseases. Taken together, these features place the bacteriophage at an intermediate point on the viral evolutionary tree and help illuminate the overall evolutionary path taken by families of viruses.

The new images show not only the outer coat of the bacteriophage, but also reveal details of its inner membrane, a poorly-understood fatty double layer beneath the coat that forms a protective barrier around the genetic material, or DNA.

"We have been intrigued by the parallels between PRD1 and adenovirus since we discovered striking similarities in their overall structure in earlier studies," says structural biologist Roger M. Burnett, Ph.D., a professor at The Wistar Institute and senior author on the Nature Structural Biology study. "Our results reveal that PRD1 also has similarities to simpler viruses and reinforce the idea that there is a continuum of viral architectures running through viruses that infect such different hosts as bacteria, plants, and animals, including humans. An appreciation of these parallels is important, as findings in one viral system may provide valuable insights into another. We have also learned more about membranes, which are very hard to study with conventional techniques, and see now how they can be involved in packaging viral DNA."

The two imaging techniques used by the researchers to dissect the structure of PRD1 are electron microscopy and X-ray crystallography. Computer modeling was used to combine images of an entire virus particle provided by the relatively low-resolution technique of electron microscopy with the high-resolution molecular structure of the coat protein obtained through X-ray crystallography. The resultant "quasi-atomic" structure of the proteins forming the outer envelope of the virus was then stripped away by a kind of graphical "surgery" to reveal details of the other molecules forming the viral interior.

###The lead author on the Nature Structural Biology study is Carmen San Martin, Ph.D., a member of Burnett's laboratory. Co-authors on the study are Juha T. Huiskonen, Jaana K. H. Bamford, Sarah J. Butcher and Dennis H. Bamford of the University of Helsinki, Finland; and Stephen D. Fuller of the Wellcome Trust Center, University of Oxford, England.

Funding for the research was provided by the Human Frontiers Science Program, the National Science Foundation, the National Institutes of Health, the Fannie E. Rippel Foundation, and the Academy of Finland.

The Wistar Institute is an independent nonprofit biomedical research institution dedicated to discovering the causes and cures for major diseases, including cancer, cardiovascular disease, autoimmune disorders, and infectious diseases. Founded in 1892 as the first institution of its kind in the nation, The Wistar Institute today is a National Cancer Institute-designated Cancer Center - one of only eight focused on basic research. Discoveries at Wistar have led to the development of vaccines for such diseases as rabies and rubella, the identification of genes associated with breast, lung, and prostate cancer, and the development of monoclonal antibodies and other significant research technologies and tools.


Story Source:

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


Cite This Page:

The Wistar Institute. "Newly Revealed Viral Structure Suggests A Continuum In The Evolution Of Viruses." ScienceDaily. ScienceDaily, 26 September 2002. <www.sciencedaily.com/releases/2002/09/020926065032.htm>.
The Wistar Institute. (2002, September 26). Newly Revealed Viral Structure Suggests A Continuum In The Evolution Of Viruses. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2002/09/020926065032.htm
The Wistar Institute. "Newly Revealed Viral Structure Suggests A Continuum In The Evolution Of Viruses." ScienceDaily. www.sciencedaily.com/releases/2002/09/020926065032.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) — You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
Get A Mortgage, Receive A Cat — Only In Russia

Get A Mortgage, Receive A Cat — Only In Russia

Newsy (Sep. 2, 2014) — The incentive is in keeping with a Russian superstition that it's good luck for a cat to be the first to cross the threshold of a new home. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Sharks Off the Menu and on the Tourist Trail in Palau

Sharks Off the Menu and on the Tourist Trail in Palau

AFP (Sep. 2, 2014) — Tourists in Palau clamour to dive with sharks thanks to a pioneering conservation initiative -- as the island nation plans to completely ban commercial fishing in its vast ocean territory. 01:15 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