4P6I

Crystal structure of the Cas1-Cas2 complex from Escherichia coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.225 
  • R-Value Observed: 0.226 

wwPDB Validation 3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Cas1-Cas2 complex formation mediates spacer acquisition during CRISPR-Cas adaptive immunity.

Nunez, J.K.Kranzusch, P.J.Noeske, J.Wright, A.V.Davies, C.W.Doudna, J.A.

(2014) Nat Struct Mol Biol 21: 528-534

  • DOI: 10.1038/nsmb.2820
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • The initial stage of CRISPR-Cas immunity involves the integration of foreign DNA spacer segments into the host genomic CRISPR locus. The nucleases Cas1 and Cas2 are the only proteins conserved among all CRISPR-Cas systems, yet the molecular functions ...

    The initial stage of CRISPR-Cas immunity involves the integration of foreign DNA spacer segments into the host genomic CRISPR locus. The nucleases Cas1 and Cas2 are the only proteins conserved among all CRISPR-Cas systems, yet the molecular functions of these proteins during immunity are unknown. Here we show that Cas1 and Cas2 from Escherichia coli form a stable complex that is essential for spacer acquisition and determine the 2.3-Å-resolution crystal structure of the Cas1-Cas2 complex. Mutations that perturb Cas1-Cas2 complex formation disrupt CRISPR DNA recognition and spacer acquisition in vivo. Active site mutants of Cas2, unlike those of Cas1, can still acquire new spacers, thus indicating a nonenzymatic role of Cas2 during immunity. These results reveal the universal roles of Cas1 and Cas2 and suggest a mechanism by which Cas1-Cas2 complexes specify sites of CRISPR spacer integration.


    Organizational Affiliation

    1] Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA. [2] Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, California, USA. [3] Department of Chemistry, University of California, Berkeley, Berkeley, California, USA. [4] Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CRISPR-associated endoribonuclease Cas2
A, B
103Escherichia coli K-12Mutation(s): 0 
Gene Names: ygbFcas2b2754JW5438
EC: 3.1
Find proteins for P45956 (Escherichia coli (strain K12))
Go to UniProtKB:  P45956

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
CRISPR-associated endonuclease Cas1
C, D, E, F
305Escherichia coli K-12Mutation(s): 0 
Gene Names: b2755cas1JW2725pstSygbT
EC: 3.1
Find proteins for Q46896 (Escherichia coli (strain K12))
Go to UniProtKB:  Q46896
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.225 
  • R-Value Observed: 0.226 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 94.875α = 90
b = 125.696β = 102.74
c = 99.306γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Science Foundation (NSF, United States)United States1244557

Revision History 

  • Version 1.0: 2014-05-07
    Type: Initial release
  • Version 1.1: 2014-05-21
    Changes: Database references
  • Version 1.2: 2014-10-01
    Changes: Database references
  • Version 1.3: 2015-01-07
    Changes: Database references
  • Version 1.4: 2017-09-06
    Changes: Author supporting evidence, Derived calculations, Other, Source and taxonomy
  • Version 1.5: 2019-11-27
    Changes: Author supporting evidence