Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MIT-led team: viruses change shape to infect us

05.01.2005


The binding of a viral RNA and a viral protein brings about a physical transformation that dupes host cells into enthusiastically copying the invading pathogen, according to a team of researchers from MIT, Harvard, and Harvard Medical School.



In the December 17 issue of Science, collaborators led by Professor Lee Gehrke of the Harvard-MIT Division of Health Sciences and Technology published dramatic three-dimensional images of RNA-protein interactions in alfalfa mosaic virus (AMV), a safe model for investigating single-strand, positive-sense RNA viruses. AMV’s dangerous relatives include flaviviruses that cause dengue fever, Japanese encephalitis and West Nile disease.

Gehrke and other molecular virologists knew that AMV was not infectious unless its genomic RNAs bound viral protein, but the details were unknown. Laura Guogas, a postdoctoral associate in Gehrke’s lab, decided to seek answers with x-ray crystallography.


What Guogas found is "stunning and unexpected," says James Hogle, a Harvard Medical School (HMS) structural biologist and professor of biological chemistry and molecular pharmacology. He and David Filman, also of HMS, contributed to this study.

RNA binding turned the viral coat protein from a floppy coil into a tight, springy helix. The RNA, a smooth strand punctuated by bumpy "hairpin structures," developed a kink that looks like a mountain turn on the Tour de France. The researchers attribute this kink to the formation of additional links between the two sides of the hairpins, another surprise from the three-dimensional structure. RNA and protein fold together in a way that locks them into place.

This distinctive, stable structure turns one end of the viral RNA into a handsome stranger. "It sticks out like a beacon compared with other RNAs in the cell," says Gehrke, who proposes that the host cell’s replicating enzyme "jumps right on" and begins making more copies of the infecting virus.

Ordinarily, the translation of the viral RNAs into protein is triggered by a string of a particular RNA building block, adenosine, at one end of a typical RNA, a so-called "poly-A tail" that flaviviruses lack. AMV substitutes the striking RNA-protein complex that Guogas identified; other viruses in the family probably form different structures that make the ends of their RNA attractive to the cell’s translation and replicating machinery.

Future research will look for ways to translate differences between cellular and flavivirus RNAs into vaccines and treatments for dengue fever, West Nile virus, and similar infections. The researchers hope to build on the synergy between biochemistry and structural biology demonstrated by Guogas’s study. "This project is a great example of the role a talented student can play in a collaboration between two labs with complementary interests and expertise," says Hogle.

Elizabeth A. Thomson | MIT News Office
Further information:
http://www.mit.edu

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>