Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Detailed chemical structure of P22 virus resolved

08.03.2017

Scientists at Baylor College of Medicine, the Lawrence Berkeley National Laboratory, Massachusetts Institute of Technology and Purdue University have completed a model of unprecedented near-atomic resolution of the chemical structure of the P22 virus. The study appears in the Proceedings of the National Academy of Sciences.

For nearly 30 years the laboratory of Dr. Wah Chiu, Distinguished Service Professor and Alvin Romansky Professor of Biochemistry and Molecular Biology at Baylor and senior author of the paper, has been applying electron cryomicroscopy and computer reconstruction techniques to determine the 3-D structures of biological nanomachines, such as the P22 virus.


Complete capsid of bacteriophage P22 generated with validated atomic models that were derived from the high-resolution cryoEM density map.

Credit: C.Hryc and the Chiu Lab

This virus is a bacteriophage -- a type that infects bacteria, in this case Salmonella -and has been extensively studied through genetics, biochemistry and biophysics. Nevertheless, its precise chemical structure has remained unresolved.

"In 2011, we published a structure of the P22 virus that allowed us to trace out a majority of the protein backbone with certainty, but we could not visualize the fine details, such as individual, small side chains," said co-first author Corey Hryc, graduate student in the Chiu lab.

"Since then, the technology in the microscopes has improved; we have new detectors that allow us to record better- and higher-contrast images to improve the resolution of our data. In addition, we have new processing algorithms that allow us to increase our ability to resolve the structure."

A new era of precision cryo-electron microscopy

"The novelty of this work is that we took more than 20,000 two-dimensional individual images of the P22 virus with the electron cryomicroscope and combined them using computational protocols to produce a 3-D map with unprecedented detail," Chiu said.

"By comparison, the two-dimensional images we take of the virus would be like taking thousands of photos of your head randomly, in different places, and then fit the photos where they would belong in a 3-D space using a computer," Hryc said. "In this way, we could probably create a 3-D model of your head, and, if the photos were X-ray images, we could see the insides, too."

The analysis of the high-resolution map of the P22 virus allowed the researchers to see in great detail all the building blocks of the proteins in the virus, the amino acids, including their side chains and how they interact with neighbor amino acids.

"The minute details we obtain now of biological structures with this approach give us more information about their biochemistry than before," Hryc said. "I think that's exciting."

"Thanks to this exquisite structural detail, we have determined the protein chemistry of the P22 virus," Chiu said. "I think it is important that we provide detailed annotations with the structure so other researchers can use it for their future experiments."

"Without the annotations you would think that everything in the map is essentially equivalent from a modeling standpoint, but this is not the case," Hryc said. "Some of these amino acids are much more clearly visible than others, particularly in the interactions between the different components of the virus."

"Hryc has set the standard for precision cryo-electron microscopy," Chiu said.

###

Other contributors to this work include co-first author Dong-Hua Chen currently at Stanford University, Pavel V. Afonine, Joanita Jakana, Zhao Wang, Cameron Haase-Pettingell, Wen Jiang, Paul D. Adams, Jonathan A. King and Michael F. Schmid.

This work was supported by the National Institutes of Health (P41GM103832, R01GM079429, P01GM063210 and PN2EY016525), the Robert Welch Foundation (Q1242) and The National Library of Medicine Training Program in Biomedical Informatics (Grant T15LM007093) awarded to the Keck Center of the Gulf Coast Consortia.

Media Contact

Graciela Gutierrez
ggutierr@bcm.edu
713-798-4710

 @bcmhouston

https://www.bcm.edu/news 

Graciela Gutierrez | EurekAlert!

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>