MONDAY, SEPTEMBER 26, 2016

RNA discovery soon may stop viruses dead in their tracks

Researchers said they have cracked a genetic code to better understand several viruses. | Courtesy of sciencedaily.com

Researchers recently broke a code that is crucial in understanding and combatting a large group of viruses, including the common cold and polio, the University of Leeds said Wednesday.

The code is part of a ribonucleic acid (RNA) sequence that creates a form of viral genome.

The researchers from the University of Leeds and the University of York have published their study in a paper in the Proceedings of the National Academy of Sciences (PNAS) Early Edition. They said breaking the code will dislocate the virus, stopping it from recreating itself in the RNA, and thus stopping the illness.

The most basic kind of virus is a single-strand RNA virus. Despite their simplicity, these viruses are some of the most damaging and dangerous, such as HIV, hepatitis C and norovirus.

Rhinovirus causes the common cold. Newer viruses such as encephalitis and chikungunya come from the rhinovirus family.

“If you think of this as molecular warfare, these are the encrypted signals that allow a virus to deploy itself effectively," Peter Stockley, leader of the study and a professor of biological chemistry at the University of Leeds, said. "Now, for this whole class of viruses, we have found the 'Enigma Machine' -- the coding system that was hiding these signals from us. We have shown that not only can we read these messages, but we can jam them and stop the viruses' deployment."

In 2012, the Leeds team published its study of a single-strand RNA virus’s behavior at a single-molecule level. Researchers watched the RNA virus condense itself into its outer shell, which requires the virus to precisely fold into the correct shape of the protective viral protein coat. The virus accomplishes this feat in milliseconds.

Next, researchers wanted to discover how the virus did this. Mathematicians from the University of York collaborated with the Leeds team to create algorithms that would break the code in computerized models of the RNA’s coding system.

Then the team used single-molecule fluorescence spectroscopy to observe the codes within the satellite tobacco necrosis virus. This is a single-strand RNA plant virus.

The researchers plan to create molecules that will intercept the code, breaking it to the point of stopping the virus from spreading. Their computerized models and single-molecule detection capabilities may be combined to offer a new direction for drug discovery.

“We have understood for decades that the RNA carries the genetic messages that create viral proteins, but we didn't know that hidden within the stream of letters we use to denote the genetic information is a second code governing virus assembly,” Dr. Roman Tuma, reader in Biophysics at the University of Leeds, said. “It is like finding a secret message within an ordinary news report and then being able to crack the whole coding system behind it.”

Next, the team will broaden its focus to include animal viruses.