Protein displacement by DExH/D "RNA helicases" without duplex unwinding.
Members of the DExH/D superfamily of nucleic acid-activated nucleotide triphosphatases are essential for virtually all aspects of RNA metabolism, including pre-messenger RNA splicing, RNA interference, translation, and nucleocytoplasmic trafficking. Physiological substrates for these enzymes are thought to be regions of double-stranded RNA, because several DExH/D proteins catalyze strand separation in vitro. These "RNA helicases" can also disrupt RNA-protein interactions, but it is unclear whether this activity is coupled to duplex unwinding. Here we demonstrate that two unrelated DExH/D proteins catalyze protein displacement independently of duplex unwinding. Therefore, the essential functions of DExH/D proteins are not confined to RNA duplexes but can be exerted on a wide range of ribonucleoprotein substrates.
Fairman
Margaret E
ME
Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
Maroney
Patricia A
PA
Wang
Wen
W
Bowers
Heath A
HA
Gollnick
Paul
P
Nilsen
Timothy W
TW
Jankowsky
Eckhard
E
D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000378:metabolism*; D053487:DEAD-box RNA Helicases; D005091:Exons; D005656:Fungal Proteins / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D020365:RNA Helicases / Q000378:metabolism*; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism*; D012326:RNA Splicing; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014616:Vaccinia virus / Q000201:enzymology
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; C079092:MtrB protein, Bacteria; D012322:RNA Precursors; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; D012313:RNA; D000255:Adenosine Triphosphate; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases