CshA Helicase

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 

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This is version 1.2 of the entry. See complete history


Structural Insights into a Unique Dimeric DEAD-Box Helicase CshA that Promotes RNA Decay.

Huen, J.Lin, C.-L.Golzarroshan, B.Yi, W.-L.Yang, W.Z.Yuan, H.S.

(2017) Structure 25: 469-481

  • DOI: https://doi.org/10.1016/j.str.2017.01.012
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    CshA is a dimeric DEAD-box helicase that cooperates with ribonucleases for mRNA turnover. The molecular mechanism for how a dimeric DEAD-box helicase aids in RNA decay remains unknown. Here, we report the crystal structure and small-angle X-ray scattering solution structure of the CshA from Geobacillus stearothermophilus. In contrast to typical monomeric DEAD-box helicases, CshA is exclusively a dimeric protein with the RecA-like domains of each protomer forming a V-shaped structure. We show that the C-terminal domains protruding outward from the tip of the V-shaped structure is critical for mediating strong RNA binding and is crucial for efficient RNA-dependent ATP hydrolysis. We also show that RNA remains bound with CshA during ATP hydrolysis cycles and thus bulk RNAs could be unwound and degraded in a processive manner through cooperation between exoribonucleases and CshA. A dimeric helicase is hence preserved in RNA-degrading machinery for efficient RNA turnover in prokaryotes and eukaryotes.

  • Organizational Affiliation

    Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 11529, ROC.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
DEAD-box ATP-dependent RNA helicase CshAA [auth B],
B [auth A]
429Geobacillus stearothermophilus 10Mutation(s): 0 
Gene Names: cshAGT50_10605
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.489α = 90
b = 96.314β = 95.21
c = 83.773γ = 90
Software Package:
Software NamePurpose

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-03-22
    Type: Initial release
  • Version 1.1: 2017-11-08
    Changes: Database references
  • Version 1.2: 2023-11-08
    Changes: Data collection, Database references, Refinement description