Molecular basis of Gabija anti-phage supramolecular assemblies.
Nat Struct Mol Biol
; 31(8): 1243-1250, 2024 Aug.
Article
en En
| MEDLINE
| ID: mdl-38627580
ABSTRACT
As one of the most prevalent anti-phage defense systems in prokaryotes, Gabija consists of a Gabija protein A (GajA) and a Gabija protein B (GajB). The assembly and function of the Gabija system remain unclear. Here we present cryo-EM structures of Bacillus cereus GajA and GajAB complex, revealing tetrameric and octameric assemblies, respectively. In the center of the complex, GajA assembles into a tetramer, which recruits two sets of GajB dimer at opposite sides of the complex, resulting in a 44 GajAB supramolecular complex for anti-phage defense. Further biochemical analysis showed that GajA alone is sufficient to cut double-stranded DNA and plasmid DNA, which can be inhibited by ATP. Unexpectedly, the GajAB displays enhanced activity for plasmid DNA, suggesting a role of substrate selection by GajB. Together, our study defines a framework for understanding anti-phage immune defense by the GajAB complex.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Bacillus cereus
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Proteínas Bacterianas
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Modelos Moleculares
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Microscopía por Crioelectrón
Idioma:
En
Revista:
Nat Struct Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos