MAR 04, 2015 9:15 AM PST

Huge Virus Exposed in 3-D with X-ray Laser

WRITTEN BY: Judy O'Rourke
For the first time, researchers have produced a 3-D image revealing part of the inner structure of an intact, infectious virus, using a unique X-ray laser at the Department of Energy's SLAC National Accelerator Laboratory. The virus, called Mimivirus, is in a curious class of "giant viruses" discovered just over a decade ago.

The experiment establishes a new technique for reconstructing the 3-D structure of many types of biological samples from a series of X-ray laser snapshots.
This computerized rendering shows a cutaway view of a collection of about 200 X-ray patterns, produced in an experiment at SLAC's Linac Coherent Light Source X-ray laser. The images were combined to produce a 3-D rendering of an intact Mimivirus, a giant virus that was at first mislabeled as a bacterium because of its size.
"Ever since I started in this field of X-ray laser research, this has always been the dream - to acquire 3-D images of real biological samples," says Tomas Ekeberg, PhD, biophysicist, Uppsala University, Sweden, and lead author of the study, published March 2 in Physical Review Letters. "This is fantastic - it's a breakthrough in our research."

Mimivirus is so big - its volume is thousands of times larger than the smallest viruses and even larger than some bacteria - that it was misclassified as a bacterium until 2003. Subsequent discoveries have found other giant viruses, some of which are even larger.

Mimivirus is also genetically complex, with nearly 1,000 major genes compared to only a handful in the HIV virus.

Scientists have been trying to determine the inner structure of these giant viruses to learn more about their origins: For example, did they borrow genes over time from the host organisms they infect, like amoebas? Did they precede cell-based life or devolve from cell-based organisms?

"We can see quite clearly that the inside of these viruses is not uniform," Ekeberg says.

This same general feature had also been seen before using an electron-based imaging technique with frozen samples, and LCLS allows studies of viruses and other biological samples in a more natural, intact state. Researchers said that LCLS shows promise for achieving sharper images that reveal more inner details in the future because of the uniquely intense, penetrating power of its X-rays.

The same technique was recently used to study bacterial cell structures. LCLS managers have launched an initiative with the scientific community to improve techniques for imaging intact, biological particles that are difficult to study.

"The next Holy Grail is to study large, single proteins at LCLS," says Janos Hajdu, PhD, professor, biophysics, Uppsala, and a pioneer in biological particle imaging.

[Source: SLAC National Accelerator Laboratory]
About the Author
  • Judy O'Rourke worked as a newspaper reporter before becoming chief editor of Clinical Lab Products magazine. As a freelance writer today, she is interested in finding the story behind the latest developments in medicine and science, and in learning what lies ahead.
You May Also Like
SEP 23, 2021
Clinical & Molecular DX
Skin Microbiome Analysis Gets Cleaned Up
SEP 23, 2021
Skin Microbiome Analysis Gets Cleaned Up
  Our skin is home to a carnival of millions of bacteria, fungi, and viruses that together form the dermal microbio ...
SEP 20, 2021
Microbiology
Antibiotics and Viruses Team Up to Kill Drug-Resistant Bugs
SEP 20, 2021
Antibiotics and Viruses Team Up to Kill Drug-Resistant Bugs
Before antibiotics became a common treatment for infections, researchers considered using viruses that infect bacteria, ...
OCT 05, 2021
Immunology
Monkey Gene Snares Viruses, Inspires Future Antivirals
OCT 05, 2021
Monkey Gene Snares Viruses, Inspires Future Antivirals
Many of the deadly viruses that affect humans—including Ebola and HIV—have animal origins. These infectious ...
OCT 03, 2021
Coronavirus
Merck's COVID-19 Drug Halves Risk of Death in Mild & Moderate Cases
OCT 03, 2021
Merck's COVID-19 Drug Halves Risk of Death in Mild & Moderate Cases
While Dr. Anthony Fauci of NIAID is already stressing that people should still get vaccinated to help reduce COVID-19 in ...
OCT 14, 2021
Microbiology
Leprosy Has Been Detected in Wild Chimpanzees for the First Time
OCT 14, 2021
Leprosy Has Been Detected in Wild Chimpanzees for the First Time
Leprosy has been infecting people since ancient times, and is estimated to have caused about 202,000 new infections in 2 ...
NOV 19, 2021
Cell & Molecular Biology
Viral RNA Can Hijack the Host by Assuming a tRNA-Like Structure
NOV 19, 2021
Viral RNA Can Hijack the Host by Assuming a tRNA-Like Structure
Many viruses have genomes made of RNA. In human cells, messenger RNA (mRNA) molecules act as intermediates; cellular mac ...
Loading Comments...