Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Purdue researchers expose ’docking bay’ for viral attack

19.08.2003


Imagine a virus and its cellular target as two spacecraft – the virus sporting a tiny docking bay that allows it to invade its victim. Purdue University researchers have taken a close-up picture of one virus’ docking bay, work that could have implications for both medicine and nanotechnology.


This is a close-up image of the T4 virus baseplate, which the virus uses to attach itself to its E. coli bacterium host. The 16 types of proteins that form the baseplate are color-coded. More than 150 total protein molecules make up the baseplate, a complex molecular machine that changes configuration when it bonds with the E. coli cell membrane. Further analysis of the baseplate could lead to advances in both medicine and nanotechnology. (Graphic/Purdue University Department of Biology)


Shown is an image of the T4 virus studied by Michael Rossmann’s group. The virus carries its genetic material in the head section, then injects it into the E. coli bacterium through its tail after the baseplate attaches itself to the cell membrane. (Graphic/Purdue University Department of Biology



Using advanced imaging techniques, an international team of biologists led by Michael Rossmann of Purdue, Vadim Mesyanzhinov in Moscow and Fumio Arisaka at the Tokyo Institute of Technology has analyzed the structure of part of the T4 virus, which commonly infects E. coli bacteria. The part they analyzed, called the baseplate, is a complex structure made of 16 types of proteins that allows T4 to attach itself to the surface of E. coli in order to inject its own deadly genetic material. Their work has produced the clearest picture ever obtained of the baseplate, which plays a critical role in the initial stages of viral infection.

"We now have a fairly complete picture of the baseplate, the part of the virus that latches onto its cellular victim," said Rossmann, who is Hanley Distinguished Professor of Biological Sciences in Purdue’s School of Science. "Armed with this knowledge, we should obtain a better understanding of how this virus injects its genetic material into its host. It could be the key to stopping the process – or even harnessing it to benefit humanity."


The paper appears in the latest issue (Sunday, 8/17) of Nature Structural Biology.

While T4 is perhaps not as well known as the viruses that cause the flu, it is an old friend of viral researchers as an invader of the E. coli bacterium, which itself can threaten human health. Viruses that attack bacteria, called bacteriophages, are readily studied because a virus that attacks a unicellular host can often be observed and manipulated more easily.

"Mesyanzhinov, Arisaka and I discussed the possibility of examining T4 in closer detail," said Rossmann. "It’s a very complicated structure consisting of more than 150 protein molecules, and we wanted to know how they were put together. So we decided to take a close look."

It had been common scientific knowledge that the baseplate was a complicated but beautiful mechanism, one which changed its conformation from a hexagon to a star shape as it formed the irrevocable bond between virus and bacterium. Analysis of its protein building blocks required the use of both electron microscopy, needed to resolve the shapes and relationships between the proteins, and X-ray crystallography, needed for high-resolution images of the atoms within them. Each of the three researchers contributed some of the technology necessary for the analysis, which eventually revealed the structure of the baseplate.

"There are several steps a virus takes to infect a host cell," Rossmann said. "Scientists have long known what the steps were, but no one had ever examined them on a molecular level before. This research should allow us to analyze the initial events in a viral attack. Such knowledge could be useful for targeting bacterial viruses to kill invading bacteria as an alternative to antibiotic compounds."

While viruses are not generally thought of as prospective friends to mankind, many attack the very bacteria that cause common human illnesses, giving them potential as antibiotics.

"T4 attacks E. coli, which is well known as a threat to human health," Rossmann said. "Many other bacteriophages also have structures similar to T4. If we could modify the proteins in the baseplate’s attachment fibers, it might enable T4 to destroy harmful bacteria. This research could be a step in that direction."

Nanotechnology applications also are possible.

"The baseplate of this virus is essentially a complex molecular machine," Rossmann said. "We have now obtained a clear picture of its structure, which has allowed us to suggest how it works. Building nanomachines will likely be easier if we can borrow some mechanisms already proven by nature."

Such applications are admittedly pie in the sky for the moment, and Rossmann said the most valuable result of the research is the fundamental knowledge it reveals about viruses.

"We now have a close-up image of the machinery that guides the steps taken when a virus infects a cell," he said. "We hope further analyses will show even greater detail."

This research was funded in part by grants from the National Science Foundation, the Howard Hughes Medical Institute and the Human Frontiers Science Program.

Rossmann’s team is associated with Purdue’s Markey Center for Structural Biology, which consists of laboratories that use a combination of cryoelectron microscopy, crystallography and molecular biology to elucidate the processes of viral entry, replication and pathogenesis.

Writer: Chad Boutin, (765) 494-2081, cboutin@purdue.edu

Sources: Michael G. Rossmann, (765) 494-4911, mgr@indiana.bio.purdue.edu

Petr G. Leiman, (765) 494-4925, leiman@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Chad Boutin | Purdue News
Further information:
http://news.uns.purdue.edu/html4ever/030818.Rossmann.baseplate.html
http://www.nature.com/naturestructuralbiology

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>