Involvement of the Pseudomonas aeruginosa MexAB-OprM efflux pump in the secretion of the metallophore pseudopaline.
Mol Microbiol
; 115(1): 84-98, 2021 01.
Article
em En
| MEDLINE
| ID: mdl-32896017
ABSTRACT
To overcome the metal restriction imposed by the host's nutritional immunity, pathogenic bacteria use high metal affinity molecules called metallophores. Metallophore-mediated metal uptake pathways necessitate complex cycles of synthesis, secretion, and recovery of the metallophore across the bacterial envelope. We recently discovered staphylopine and pseudopaline, two members of a new family of broad-spectrum metallophores important for bacterial survival during infections. Here, we are expending the molecular understanding of the pseudopaline transport cycle across the diderm envelope of the Gram-negative bacterium Pseudomonas aeruginosa. We first explored pseudopaline secretion by performing in vivo quantifications in various genetic backgrounds and revealed the specific involvement of the MexAB-OprM efflux pump in pseudopaline transport across the outer membrane. We then addressed the recovery part of the cycle by investigating the fate of the recaptured metal-loaded pseudopaline. To do so, we combined in vitro reconstitution experiments and in vivo phenotyping in absence of pseudopaline transporters to reveal the existence of a pseudopaline modification mechanism, possibly involved in the metal release following pseudopaline recovery. Overall, our data allowed us to provide an improved molecular model of secretion, recovery, and fate of this important metallophore by P. aeruginosa.
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Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Proteínas de Membrana Transportadoras
/
Pseudomonas aeruginosa
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Proteínas da Membrana Bacteriana Externa
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
França