8CQB image
Entry Detail
PDB ID:
8CQB
EMDB ID:
Keywords:
Title:
Cryo-EM structure of the human GBP1 dimer bound to GDP-AlF3
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2023-03-04
Release Date:
2024-03-13
Method Details:
Experimental Method:
Resolution:
3.70 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Guanylate-binding protein 1
Chain IDs:A, B
Chain Length:592
Number of Molecules:2
Biological Source:Homo sapiens
Primary Citation
Structural basis of antimicrobial membrane coat assembly by human GBP1.
Nat.Struct.Mol.Biol. 32 172 184 (2025)
PMID: 39394410 DOI: 10.1038/s41594-024-01400-9

Abstact

Guanylate-binding proteins (GBPs) are interferon-inducible guanosine triphosphate hydrolases (GTPases) mediating host defense against intracellular pathogens. Their antimicrobial activity hinges on their ability to self-associate and coat pathogen-associated compartments or cytosolic bacteria. Coat formation depends on GTPase activity but how nucleotide binding and hydrolysis prime coat formation remains unclear. Here, we report the cryo-electron microscopy structure of the full-length human GBP1 dimer in its guanine nucleotide-bound state and describe the molecular ultrastructure of the GBP1 coat on liposomes and bacterial lipopolysaccharide membranes. Conformational changes of the middle and GTPase effector domains expose the isoprenylated C terminus for membrane association. The α-helical middle domains form a parallel, crossover arrangement essential for coat formation and position the extended effector domain for intercalation into the lipopolysaccharide layer of gram-negative membranes. Nucleotide binding and hydrolysis create oligomeric scaffolds with contractile abilities that promote membrane extrusion and fragmentation. Our data offer a structural and mechanistic framework for understanding GBP1 effector functions in intracellular immunity.

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