Repetitive RNA unwinding by RNA helicase A facilitates RNA annealing

Details

• Alternative Title:
  Nucleic Acids Res
• Personal Author:
  Koh, Hye Ran ; Xing, Li ; Kleiman, Lawrence ; Myong, Sua
• Description:
  Helicases contribute to diverse biological processes including replication, transcription and translation. Recent reports suggest that unwinding of some helicases display repetitive activity, yet the functional role of the repetitiveness requires further investigation. Using single-molecule fluorescence assays, we elucidated a unique unwinding mechanism of RNA helicase A (RHA) that entails discrete substeps consisting of binding, activation, unwinding, stalling and reactivation stages. This multi-step process is repeated many times by a single RHA molecule without dissociation, resulting in repetitive unwinding/rewinding cycles. Our kinetic and mutational analysis indicates that the two double stand RNA binding domains at the N-terminus of RHA are responsible for such repetitive unwinding behavior in addition to providing an increased binding affinity to RNA. Further, the repetitive unwinding induces an efficient annealing of a complementary RNA by making the unwound strand more accessible. The complex and unusual mechanism displayed by RHA may help in explaining how the repetitive unwinding of helicases contributes to their biological functions.
• Subjects:
  DEAD-box RNA Helicases HEK293 Cells Humans Nucleic Acid Enzymes Protein Structure, Tertiary RNA, Double-Stranded RNA-Binding Proteins
• Source:
  Nucleic Acids Res. 2014; 42(13):8556-8564.
• Pubmed ID:
  24914047
• Pubmed Central ID:
  PMC4117756
• Document Type:
  Journal Article
• Funding:
  1DP2GM105453/DP/NCCDPHP CDC HHS/United States ; DP2 GM105453/GM/NIGMS NIH HHS/United States ; Canadian Institutes of Health Research/Canada
• Volume:
  42
• Issue:
  13
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:f2d4b76a21e03c08fc5104bbf089ebdcbbdde65e6625cce979bf8755f8fafc4e
• Download URL:
  https://stacks.cdc.gov/view/cdc/32267/cdc_32267_DS1.pdf
• File Type:
  [PDF - 3.00 MB ]