Molecular biologists at The University of Texas at Austin have solved one of the mysteries of how double-stranded RNA is remodeled inside cells in both their normal and disease states. The discovery may have implications for treating cancer and viruses in humans. DEAD-box proteins, which are ancient enzymes found in all forms of life, function as recycling "nanopistons." They use chemical energy to clamp down and pry open RNA strands, thereby enabling the formation of new structures. DEAD-box proteins are the largest family of what are known as " RNA helicases," which unwind RNA.
The mechanism is almost certainly universal to the entire family of the proteins, however, and therefore to all domains of life. Every DEAD-box protein that we know about has the same structure and they are particularly useful as a universal remodeling device because they can bind to any RNA. They recognize the geometry of double-stranded RNA and are not sequence-specific. This flexibility of DEAD-box proteins is essential to the functioning of healthy cells, which rely on a range of RNA molecules for basic processes, including protein synthesis. It's also hijacked in cancers, where over-expression of DEAD-box proteins may help drive uncontrolled cell proliferation, and in infections caused by bacteria, fungi, and viruses, which rely on specific DEAD-box proteins for their propagation.