Lambowitz, Mallam and their colleagues uncovered this mechanism in Mss116p, a DEAD-box protein in yeast. 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," said Lambowitz, "and they all presumably use the same mechanism."
Lambowitz said that the Mss116p proteins are particularly useful as a universal remodeling device because they can bind to any RNA.
"It recognizes the geometry of double-stranded RNA," he said. "It doesn't care about the sequence, and doesn't care about what it that particular RNA molecule's function is. It just sees it and binds and for that reason can be incorporated into many different cellular processes."
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.
"This is basic science," said Lambowitz. "Its major significance is in understanding, at the root, how this mechanism works. But when you understand how DEAD-box proteins function both in normal cellular processes and in disease processes, you can absolutely begin to think about how they might be targeted in things like cancer and viruses."
"You can even envision, in the far future, how they be incorporated into artificial nanomachines, for switches and other mechanical devices inside and outside the cell."
|Contact: Daniel Oppenheimer|
University of Texas at Austin