37UO | pdb_000037uo

Gammacoronavirus dual dsRNA-bound IBV nsp15 (same trimer)

• PDB DOI: https://doi.org/10.2210/pdb37UO/pdb
• EM Map EMD-78494: EMDB EMDataResource

• Classification: VIRAL PROTEIN/RNA
• Organism(s): Infectious bronchitis virus, synthetic construct
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2026-08-06 Released: 2026-09-09 
• Deposition Author(s): Tully, E.S., Kirchdoerfer, R.N.
• Funding Organization(s): National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.20 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental

Literature

Structural and biochemical analysis of the IBV nsp15 endoribonuclease reveals the necessity of peripheral site residues for activity

Tully, E.S., Kirchdoerfer, R.N.

(2026) bioRxiv 

• DOI: https://doi.org/10.64898/2026.08.28.747898

Biological Assembly 1  

Global Symmetry: Dihedral - D3  (Explore in 3D)
Global Stoichiometry: Homo 6-mer - A6 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 256.35 kDa 
• Atom Count: 17,639 
• Modeled Residue Count: 2,103 
• Deposited Residue Count: 2,118 
• Unique protein chains: 1
• Unique nucleic acid chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Nonstructural protein 15	A, B [auth C], C [auth D], D [auth E], E [auth F], H [auth B]	339	Infectious bronchitis virus	Mutation(s): 1  Gene Names: 1b EC: 2.7.7.48
UniProt
Find proteins for G4XMQ6 (Infectious bronchitis virus) Explore G4XMQ6  Go to UniProtKB:  G4XMQ6

Entity ID: 2
Molecule	Chains	Length	Organism	Image
RNA (5'-R(*GP*UP*AP*GP*AP*UP*UP*UP*GP*CP*UP*UP*GP*UP*UP*UP*GP*AP*UP*U)-3')	F [auth G], I	20	synthetic construct

Entity ID: 3
Molecule	Chains	Length	Organism	Image
RNA (5'-R(P*AP*AP*AP*AP*UP*CP*AP*AP*AP*CP*AP*AP*GP*CP*AP*AP*AP*UP*CP*UP*AP*C)-3')	G [auth H], J	22	synthetic construct

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.20 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC	4.6
MODEL REFINEMENT	PHENIX	1.21.2_5419
MODEL REFINEMENT	Coot	0.9.8.95

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-09-09 
Deposition Author(s): Tully, E.S., Kirchdoerfer, R.N.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)	United States	AI159945

Revision History  

• Version 1.0: 2026-09-09
  Type: Initial release