8EE7 image
Entry Detail
PDB ID:
8EE7
EMDB ID:
Keywords:
Title:
Structure of focused PtuA(dimer) and PtuB(monomer) complex
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2022-09-06
Release Date:
2024-01-03
Method Details:
Experimental Method:
Resolution:
2.72 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:PtuA
Chain IDs:A, B
Chain Length:465
Number of Molecules:2
Biological Source:Escherichia coli
Polymer Type:polypeptide(L)
Description:PtuB
Chain IDs:C
Chain Length:243
Number of Molecules:1
Biological Source:Escherichia coli
Ligand Molecules
Primary Citation
PtuA and PtuB assemble into an inflammasome-like oligomer for anti-phage defense.
Nat.Struct.Mol.Biol. 31 413 423 (2024)
PMID: 38177683 DOI: 10.1038/s41594-023-01172-8

Abstact

Escherichia coli Septu system, an anti-phage defense system, comprises two components: PtuA and PtuB. PtuA contains an ATPase domain, while PtuB is predicted to function as a nuclease. Here we show that PtuA and PtuB form a stable complex with a 6:2 stoichiometry. Cryo-electron microscopy structure of PtuAB reveals a distinctive horseshoe-like configuration. PtuA adopts a hexameric arrangement, organized as an asymmetric trimer of dimers, contrasting the ring-like structure by other ATPases. Notably, the three pairs of PtuA dimers assume distinct conformations and fulfill unique roles in recruiting PtuB. Our functional assays have further illuminated the importance of the oligomeric assembly of PtuAB in anti-phage defense. Moreover, we have uncovered that ATP molecules can directly bind to PtuA and inhibit the activities of PtuAB. Together, the assembly and function of the Septu system shed light on understanding other ATPase-containing systems in bacterial immunity.

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Primary Citation of related structures