9TQJ | pdb_00009tqj

Cryo-EM structure of AtubAB heterodimer from Heimdallarchaeia

• PDB DOI: https://doi.org/10.2210/pdb9TQJ/pdb
• EM Map EMD-56152: EMDB EMDataResource

• Classification: UNKNOWN FUNCTION
• Organism(s): Candidatus Heimdallarchaeota archaeon
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2025-12-22 Released: 2026-06-10 
• Deposition Author(s): Lowe, J., von Kugelgen, A.
• Funding Organization(s): Medical Research Council (MRC, United Kingdom), Wellcome Trust

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.50 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Asgard archaeal AtubAB tubulins form mini microtubules exhibiting dynamic instability

Lowe, J., von Kugelgen, A.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Homo 2-mer - A2 

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

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 95 kDa 
• Atom Count: 6,016 
• Modeled Residue Count: 774 
• Deposited Residue Count: 861 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
AtubA	A	439	Candidatus Heimdallarchaeota archaeon	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
AtubB	B	422	Candidatus Heimdallarchaeota archaeon	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GDP (Subject of Investigation/LOI)	C [auth B]	GUANOSINE-5'-DIPHOSPHATE C10 H15 N5 O11 P2 QGWNDRXFNXRZMB-UUOKFMHZSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.50 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	RELION	5.0

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-06-10 
Deposition Author(s): Lowe, J., von Kugelgen, A.

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Funding Organization	Location	Grant Number
Medical Research Council (MRC, United Kingdom)	United Kingdom	U105184326
Wellcome Trust	United Kingdom	203276/C/16/Z
Wellcome Trust	United Kingdom	227876/Z/23/Z
Wellcome Trust	United Kingdom	227452/Z/23/Z

Revision History  

• Version 1.0: 2026-06-10
  Type: Initial release