Viral RNA Structure: New Universal Antiviral Drug?

A team of researchers at the University of Maryland – Baltimore County (UMBC) has made an important scientific discovery that may contribute to the development of… Antiviral medicine Broad-spectrum, after identifying a common structure in RNA that enteroviruses use to begin replication inside human cells.

The results of the study were published in the journal Nature Communications, and explain how the virus exploits the host cell’s molecular machinery in order to produce proteins and copy its genetic material.

What are enteroviruses?

Enteroviruses include a wide group of viruses that cause serious diseases, such as:

polio

encephalitis

Myocarditis

Common colds

These viruses begin their infection by controlling the mechanisms of the human cell as soon as they enter.

Filling a scientific gap in understanding virus reproduction

The study was led by Associate Professor of Chemistry and Biochemistry Deepak Koirala, with the participation of researcher Nabha Krishna Das, as the team succeeded in explaining an early and crucial stage of the virus’s life cycle, which is how the replication of viral genetic material begins.

This discovery explains how viruses move between two basic stages:

Production of viral proteins

Copying the viral genome to produce new viruses

The role of the “cloverleaf” structure in viral RNA

Enterovirus has a very small RNA genome, but it performs two vital functions:

Serve as instructions for making proteins

Acting as a template for copying itself

The researchers discovered the existence of an RNA structure known as the “clover leaf” that plays a pivotal role in regulating these two functions by attracting viral and human proteins to form what is known as the viral replication complex.

3CD protein: a pivotal component of reproduction

One of the most important viral proteins is 3CD, which is a dual-function protein:

The 3C segment functions as a trimmer that separates viral proteins

Part 3D acts as an RNA transcription enzyme (polymerase).

Since this type of enzyme is not found in human cells, the virus depends entirely on it.

Imaging molecular interaction with high resolution

The team used several advanced technologies, including:

X-ray crystallography

Isothermal calibration (ITC) measurement

BLI

The results showed that two complete molecules of the 3CD protein bind to the RNA structure side by side, resolving a previous scientific debate about the nature of this connection.

The switch between transcription and translation

This molecular complex acts as an on-off switch:

When 3CD binds to RNA, genome transcription begins.

When separated, the RNA is translated to produce proteins

Towards a universal antiviral medicine

Most importantly, the researchers found that the same mechanism is conserved in almost all seven types of enteroviruses studied, which means that this structure is absolutely essential and does not tolerate mutations.

This makes:

RNA structure

Interface between RNA and protein

A stable and promising drug target for the development of a single treatment that may be effective against all enteroviruses.

New opportunities for drug development

Although there are drugs in development that target the 3C and 3D proteins, Koirala asserts that:

“Targeting the RNA itself or the interaction interface between the RNA and the protein represents a new therapeutic opportunity, especially with the availability of high-resolution molecular structures.”

The importance of basic research in confronting diseases

Koirala concludes by saying that viruses have a very small genome, yet they have a tremendous ability to adapt and reproduce, stressing that:

“Understanding the basic science is the first step to translating it into effective medicines against dangerous pathogens.”