Navigation Links
Viruses, start your engines!
Date:12/29/2008

Peering at structures only atoms across, researchers have identified the clockwork that drives a powerful virus nanomotor.

Because of the motor's strength--to scale, twice that of an automobile--the new findings could inspire engineers designing sophisticated nanomachines. In addition, because a number of virus types may possess a similar motor, including the virus that causes herpes, the results may also assist pharmaceutical companies developing methods to sabotage virus machinery.

Researchers from Purdue University in West Lafayette, Ind., and the Catholic University of America in Washington, D.C., collaborated on the study that appears in the Dec. 26, 2008, issue of the journal Cell.

"The discovery of how this virus motor functions represents a significant milestone in the investigation of viral processes," says David Rockcliffe, the program director who oversees a National Science Foundation (NSF) grant that partly funded the research. "This research is a breakthrough that not only may lead to the development of a means of arresting harmful infections, but it also points to possible ways in which nano-devices could be fashioned,"

The virus in the study, called T4, is not a common scourge of people, but its host is: the bacterium Escherichia coli (E. coli). Purdue researchers studied the virus structures, such as the motor, while the Catholic University researchers isolated the virus components and performed biochemical analyses.

"T4 is what's called a 'tailed virus'," says Purdue biologist Michael Rossmann, one of the lead researchers for the study. "It is actually one of the most common types of organisms in the oceans of the world. There are many different, tailed, bacteria viruses--or phages--and all of these phages have such a motor for packaging their DNA, their genome, into their pre-formed heads."

The virus is well known to scientists. "T4 has rich history going back to 1940s when the original genetic tools to understand virus assembly were developed," adds biologist Venigalla Rao of Catholic University, also a lead researcher on the study. "T4 has been an important model system to tease out the details of basic mechanisms by which viruses assemble into infectious particles."

For the recent study, analyses involved two sophisticated instruments capable of studying structures at the nanometer (billionth of a meter) scale. One of the techniques, x-ray crystallography, showed the ordered arrays of atoms in the various structures, while another, called cryo-electron microscopy, let the researchers study the broader shape of the structures without the need for coating or drying out the specimens.

Having already determined the structures of a number of other viral components and how they self-assemble, in this study the researchers focused their attention on the small motor that some viruses use to package DNA into their "heads", protein shells also called capsids.

Not all viruses have a motor such as the one found in the T4 virus, but some viruses that cause human diseases posses molecular motors with similar functions, and likely have similar structures. T4 uses its motor to pack about 171,000 basepairs of genetic information to near-crystalline density within its 120 nanometer by 86 nanometer capsid.

The researchers found that the motor is located at the intersection of the capsid and the virus "tail" and is made of a circular array of proteins called gene product 17 (gp17). Five, two-part, gp17 proteins combine to form a pair of conjoined rings, arrayed so that their upper segments form an upper ring and their lower segments form a lower ring.

As a T4 virus assembles itself, the lower ring of the motor structure attaches to a strand of DNA, while the upper ring attaches to a capsid. The upper and lower rings have opposite charges, which allow the motor to contract and release, alternately tugging at the DNA like a ring of hands pulling on a rope.

The process draws the DNA strand upwards into the capsid where it is protected from damage, enabling the virus to survive and reproduce. After the DNA is inside the capsid, the motor falls off, and a virus tail attaches to the capsid.

Until now, researchers did not know how T4, or any other virus, accomplished the DNA packaging. According to Rao, "Since the assembly of herpes viruses closely resembles that of T4, this research might provide insights on how to manipulate herpes infections."

While many questions remain, adds Rossmann, the virus may lend itself to a variety for medical purposes. One example Rossmann cites is as a potential new weapon to fight dangerous microbes.

"Bacteriophages like T4 are a completely alternative way of dealing with unwanted bacteria. The virus can kill bacteria in its process of reproduction, so use of such viruses as antibiotics has been a long looked-for alternative to overcome the problems which we now have with antibiotics."


'/>"/>

Contact: Joshua A. Chamot
jchamot@nsf.gov
703-292-7730
National Science Foundation
Source:Eurekalert

Related biology news :

1. Viruses, oxygen and our green oceans
2. Girls who begin dieting twice as likely to start smoking
3. Shape encoding may start in the retina
4. Freshman class sparks start-up company
5. Starting university may be hazardous to your health: study
6. Stowers Institutes Hawley Lab identifies factors responsible for restart of meiotic cycle
7. Starters orders for unique Ph.D.s in sport
8. NJIT start-up company NeuroTrax named best in show
9. Alzheimers starts earlier for heavy drinkers, smokers
10. No time to lose to start thinking sustainability
11. Trustee makes donation to start new solar energy research center at Rensselaer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... May 16, 2017  Veratad Technologies, LLC ( www.veratad.com ... age and identity verification solutions, announced today they will ... 2017, May 15 thru May 17, 2017, in ... International Trade Center. Identity impacts the ... in today,s quickly evolving digital world, defining identity is ...
(Date:4/19/2017)... York , April 19, 2017 ... as its vendor landscape is marked by the presence ... market is however held by five major players - ... Together these companies accounted for nearly 61% of the ... the leading companies in the global military biometrics market ...
(Date:4/13/2017)... April 13, 2017 According to a new market ... Identity Analytics, Identity Administration, and Authorization), Service, Authentication Type, Deployment Mode, Vertical, ... Market is expected to grow from USD 14.30 Billion in 2017 to ... of 17.3%. ... MarketsandMarkets Logo ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... , ... AMRI, a global contract research, development and manufacturing ... and quality of life, will now be offering its impurity solutions as a ... requirements for all new drug products, including the finalization of ICH M7 earlier ...
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... ComplianceOnline’s Medical ... place on 7th and 8th June 2018 in San Francisco, CA. The Summit brings ... well as several distinguished CEOs, board directors and government officials from around the world ...
(Date:10/11/2017)... ... 11, 2017 , ... A new study published in Fertility ... fresh in vitro fertilization (IVF) transfer cycles. The multi-center matched cohort ... After comparing the results from the fresh and frozen transfer cohorts, the authors ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder ... local San Diego Rotary Club. The event entitled “Stem Cells and ... had 300+ attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: ...
Breaking Biology Technology: