RNA helicases: modulators of RNA structure.

RNA molecules play an essential role in many cellular processes, often as components of ribonucleoprotein complexes. Like proteins, RNA molecules adopt sequence-specific secondary and tertiary structures that are essential for function; alteration of these structures therefore provides a means of regulating RNA function. The discovery of DEAD box proteins, a large family of proteins that share several highly conserved motifs and have known or putative ATP-dependent RNA helicase activity, has provoked growing interest in the concept that regulation of RNA function may occur through local unwinding of complex RNA structures.