8J4T image
Deposition Date 2023-04-20
Release Date 2024-02-21
Last Version Date 2024-02-21
Entry Detail
PDB ID:
8J4T
Title:
GajA-GajB complex
Biological Source:
Source Organism:
Method Details:
Experimental Method:
Resolution:
3.60 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Endonuclease GajA
Gene (Uniprot):gajA
Chain IDs:A, C, E (auth: D), F (auth: B)
Chain Length:598
Number of Molecules:4
Biological Source:Bacillus cereus VD045
Polymer Type:polypeptide(L)
Molecule:Gabija protein GajB
Gene (Uniprot):gajB
Chain IDs:B (auth: G), D (auth: F), G (auth: E), H
Chain Length:494
Number of Molecules:4
Biological Source:Bacillus cereus VD045
Ligand Molecules
Primary Citation
Structural and biochemical insights into the mechanism of the Gabija bacterial immunity system.
Nat Commun 15 836 836 (2024)
PMID: 38282040 DOI: 10.1038/s41467-024-45173-7

Abstact

The Gabija system is a newly discovered bacterial immune system that consists of GajA and GajB. Here we report the cryo-EM structure of the Gabija complex from Bacillus cereus VD045 at 3.6 Å, which provides the direct evidence of interactions between GajA and GajB. The Gabija complex is an octameric ring structure with four GajA and four GajB. GajA is an OLD nucleases family protein, while GajB belongs to the SF1 helicases. The Gabija complex has sequence-specific DNA nuclease activity and prefers circular rather than linear DNA as substrate, its activity is more sensitive to concentrations change of nucleotides compared to GajA alone. Our data suggest a mechanism of Gabija immunity: the nuclease activity of Gabija complex is inhibited under physiological conditions, while it is activated by depletion of NTP and dNTP upon the replication and transcription of invading phages and cleave the circular DNA to prevent phage DNA replication.

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Primary Citation of related structures