9R7B | pdb_00009r7b

Structure and mechanism of the broad spectrum CRISPR-associated ring nuclease Crn4

• PDB DOI: https://doi.org/10.2210/pdb9R7B/pdb

• Classification: VIRAL PROTEIN
• Organism(s): Hyphomicrobiales bacterium
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2025-05-14 Released: 2025-12-03 
• Deposition Author(s): McMahon, S.A., White, M.F., Gloster, T.M.
• Funding Organization(s): European Research Council (ERC)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.10 Å
• R-Value Free: 
  0.185 (Depositor), 0.188 (DCC) 
• R-Value Work: 
  0.168 (Depositor), 0.177 (DCC) 

Starting Model: in silico

Literature

Structure and mechanism of the broad spectrum CRISPR-associated ring nuclease Crn4

McMahon, S.A., White, M.F., Graham, S., Chi, H., Hoikkala, V., Gloster, T.M.

To be published.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content 

• Total Structure Weight: 13.56 kDa 
• Atom Count: 993 
• Modeled Residue Count: 114 
• Deposited Residue Count: 128 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Crn4b	A	128	Hyphomicrobiales bacterium	Mutation(s): 0

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.10 Å
• R-Value Free:  0.185 (Depositor), 0.188 (DCC) 
• R-Value Work:  0.168 (Depositor), 0.177 (DCC) 

Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 46.34	α = 90
b = 61.33	β = 101.95
c = 42.67	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
xia2	data reduction
xia2	data scaling
PHASER	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2025-12-03 
Deposition Author(s): McMahon, S.A., White, M.F., Gloster, T.M.

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Funding Organization	Location	Grant Number
European Research Council (ERC)	European Union	101018608

Revision History  

• Version 1.0: 2025-12-03
  Type: Initial release