Killing of Gram-negative and Gram-positive bacteria by a bifunctional cell wall-targeting T6SS effector.
Proc Natl Acad Sci U S A
; 118(40)2021 10 05.
Article
em En
| MEDLINE
| ID: mdl-34588306
ABSTRACT
The type VI secretion system (T6SS) is a powerful tool deployed by Gram-negative bacteria to antagonize neighboring organisms. Here, we report that Acinetobacter baumannii ATCC 17978 (Ab17978) secretes D-lysine (D-Lys), increasing the extracellular pH and enhancing the peptidoglycanase activity of the T6SS effector Tse4. This synergistic effect of D-Lys on Tse4 activity enables Ab17978 to outcompete Gram-negative bacterial competitors, demonstrating that bacteria can modify their microenvironment to increase their fitness during bacterial warfare. Remarkably, this lethal combination also results in T6SS-mediated killing of Gram-positive bacteria. Further characterization revealed that Tse4 is a bifunctional enzyme consisting of both lytic transglycosylase and endopeptidase activities, thus representing a family of modularly organized T6SS peptidoglycan-degrading effectors with an unprecedented impact in antagonistic bacterial interactions.
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MEDLINE
Assunto principal:
Proteínas de Bactérias
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Parede Celular
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Sistemas de Secreção Tipo VI
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Bactérias Gram-Negativas
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Bactérias Gram-Positivas
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article