6AS4

Structure of a phage anti-CRISPR protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Disabling a Type I-E CRISPR-Cas Nuclease with a Bacteriophage-Encoded Anti-CRISPR Protein.

Pawluk, A.Shah, M.Mejdani, M.Calmettes, C.Moraes, T.F.Davidson, A.R.Maxwell, K.L.

(2017) MBio 8: --

  • DOI: 10.1128/mBio.01751-17
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • CRISPR (clustered regularly interspaced short palindromic repeat)-Cas adaptive immune systems are prevalent defense mechanisms in bacteria and archaea. They provide sequence-specific detection and neutralization of foreign nucleic acids such as bacte ...

    CRISPR (clustered regularly interspaced short palindromic repeat)-Cas adaptive immune systems are prevalent defense mechanisms in bacteria and archaea. They provide sequence-specific detection and neutralization of foreign nucleic acids such as bacteriophages and plasmids. One mechanism by which phages and other mobile genetic elements are able to overcome the CRISPR-Cas system is through the expression of anti-CRISPR proteins. Over 20 different families of anti-CRISPR proteins have been described, each of which inhibits a particular type of CRISPR-Cas system. In this work, we determined the structure of type I-E anti-CRISPR protein AcrE1 by X-ray crystallography. We show that AcrE1 binds to the CRISPR-associated helicase/nuclease Cas3 and that the C-terminal region of the anti-CRISPR protein is important for its inhibitory activity. We further show that AcrE1 can convert the endogenous type I-E CRISPR system into a programmable transcriptional repressor.IMPORTANCE The CRISPR-Cas immune system provides bacteria with resistance to invasion by potentially harmful viruses, plasmids, and other foreign mobile genetic elements. This study presents the first structural and mechanistic insight into a phage-encoded protein that inactivates the type I-E CRISPR-Cas system in Pseudomonas aeruginosa The interaction of this anti-CRISPR protein with the CRISPR-associated helicase/nuclease proteins Cas3 shuts down the CRISPR-Cas system and protects phages carrying this gene from destruction. This interaction also allows the repurposing of the endogenous type I-E CRISPR system into a programmable transcriptional repressor, providing a new biotechnological tool for genetic studies of bacteria encoding this type I-E CRISPR-Cas system.


    Organizational Affiliation

    Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NHis AcrE1 anti-crispr protein
A, B, C
106Pseudomonas phage JBD5Mutation(s): 0 
Find proteins for L7P7L6 (Pseudomonas phage JBD5)
Go to UniProtKB:  L7P7L6
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 96.740α = 90.00
b = 63.530β = 100.34
c = 59.460γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
PHENIXrefinement
XDSdata processing
XSCALEdata scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Canadian Institutes of Health ResearchCanadaMOP-130482
Canadian Institutes of Health ResearchCanadaMOP-136845

Revision History 

  • Version 1.0: 2017-12-20
    Type: Initial release
  • Version 1.1: 2017-12-27
    Type: Database references