Beschreibung:
<jats:p>RNA helicases are ubiquitous, highly conserved enzymes that participate in nearly all aspects of eukaryotic RNA metabolism. In vitro, helicases bind or remodel RNA or RNA‐protein complexes in an ATP‐dependent fashion, but how these activities are used in the cellular function of these enzymes has remained elusive. This is mainly because RNA targets and binding sites on these targets are not known. Here, we identify RNA targets and binding sites of the yeast DEAD‐box RNA helicase Ded1p, using an approach that combines in vivo crosslinking, affinity purification and Next Generation Sequencing. Ded1p had been implicated in translation initiation, and we find that the enzyme binds to essentially all expressed mRNAs, at multiple sites on each RNA. While the binding sites do not show identifiable sequence motifs, different binding sites on a given RNA can form short helices, and mutational analysis of the binding sites in select mRNA supports the existence of these interactions. Our data suggest that Ded1p acts as a general translation initiation factor and that the enzyme impacts higher order structure of mRNAs.</jats:p>