title: Structural insights into the mechanism of the DEAH-box RNA helicase Prp43.
abstract: The DEAH-box helicase Prp43 is a key player in pre-mRNA splicing as well as the maturation of rRNAs. The exactmodus operandiof Prp43 and of all other spliceosomal DEAH-box RNA helicases is still elusive. Here, we report crystal structures of Prp43 complexes in different functional states and the analysis of structure-based mutants providing insights into the unwinding and loading mechanism of RNAs. The Prp43•ATP-analog•RNA complex shows the localization of the RNA inside a tunnel formed by the two RecA-like and C-terminal domains. In the ATP-bound state this tunnel can be transformed into a groove prone for RNA binding by large rearrangements of the C-terminal domains. Several conformational changes between the ATP- and ADP-bound states explain the coupling of ATP hydrolysis to RNA translocation, mainly mediated by a β-turn of the RecA1 domain containing the newly identified RF motif. This mechanism is clearly different to those of other RNA helicases.
authors.affiliation: Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany.
authors.forename: Marcel J
authors.initials: MJ
authors.lastname: Tauchert
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Fourmann
authors.affiliation: Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: Reinhard
authors.identifier: 0000-0002-6403-4432
authors.initials: R
authors.lastname: Lührmann
authors.affiliation: Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany.
authors.forename: Ralf
authors.identifier: 0000-0002-1739-6086
authors.initials: R
authors.lastname: Ficner
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D002597:Chaetomium / Q000201:enzymology*; D018360:Crystallography, X-Ray; D004252:DNA Mutational Analysis; D006868:Hydrolysis; D008958:Models, Molecular; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D020365:RNA Helicases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D050505:Mutant Proteins; D012313:RNA; D000255:Adenosine Triphosphate; D020365:RNA Helicases
keywords: Chaetomium thermophilum; DHX15; S. cerevisiae; X-ray crystallography; biochemistry; biophysics; rRNA biogenesis; spliceosome; structural biology