Model for RNA tertiary structure disruption by helix capture.

<p>DEAD-box proteins (orange) associate with structured RNAs nonspecifically (left), which can result in the helicase core being positioned to interact with transiently exposed helices (center). This interaction prevents reformation of tertiary contacts by the bound helix, destabilizing the RNA tertiary structure and allowing DEAD-box proteins to use ATP to perform helix unwinding (right). The DEAD-box protein illustrated is the yeast ortholog of CYT-19, Mss116 (pdb 3I5X), and the <i>Tetrahymena</i> ribozyme shown is a model structure presented in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001981#pbio.1001981-Lehnert1" target="_blank">[62]</a>.