Crystal structure of an endonuclease

Experimental Data Snapshot

  • Resolution: 3.50 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.263 
  • R-Value Observed: 0.264 

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Two Distant Catalytic Sites Are Responsible for C2c2 RNase Activities

Liu, L.Li, X.Wang, J.Wang, M.Chen, P.Yin, M.Li, J.Sheng, G.Wang, Y.

(2017) Cell 168: 121-134.e12

  • DOI: https://doi.org/10.1016/j.cell.2016.12.031
  • Primary Citation of Related Structures:  
    5WTJ, 5WTK

  • PubMed Abstract: 

    C2c2, the effector of type VI CRISPR-Cas systems, has two RNase activities-one for cutting its RNA target and the other for processing the CRISPR RNA (crRNA). Here, we report the structures of Leptotrichia shahii C2c2 in its crRNA-free and crRNA-bound states. While C2c2 has a bilobed structure reminiscent of all other Class 2 effectors, it also exhibits different structural characteristics. It contains the REC lobe with a Helical-1 domain and the NUC lobe with two HEPN domains. The two RNase catalytic pockets responsible for cleaving pre-crRNA and target RNA are independently located on Helical-1 and HEPN domains, respectively. crRNA binding induces significant conformational changes that are likely to stabilize crRNA binding and facilitate target RNA recognition. These structures provide important insights into the molecular mechanism of dual RNase activities of C2c2 and establish a framework for its future engineering as a RNA editing tool.

  • Organizational Affiliation

    Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Collaborative Innovation Center of Genetics and Development, Shanghai 200438, China. Electronic address: ylwang@ibp.ac.cn.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CRISPR-associated endoribonuclease C2c2
A, B
1,397Leptotrichia shahii DSM 19757Mutation(s): 0 
Gene Names: c2c2cas13a
EC: 3.1
Find proteins for P0DOC6 (Leptotrichia shahii (strain DSM 19757 / CCUG 47503 / CIP 107916 / JCM 16776 / LB37))
Explore P0DOC6 
Go to UniProtKB:  P0DOC6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DOC6
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B
Experimental Data & Validation

Experimental Data

  • Resolution: 3.50 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.263 
  • R-Value Observed: 0.264 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 91.658α = 90
b = 94.231β = 90
c = 338.218γ = 90
Software Package:
Software NamePurpose
HKL-3000data scaling
HKL-3000data processing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-02-08
    Type: Initial release
  • Version 1.1: 2017-08-30
    Changes: Data collection