Novel coordination of lipopolysaccharide modifications in Vibrio cholerae promotes CAMP resistance.
Mol Microbiol
; 106(4): 582-596, 2017 Nov.
Article
em En
| MEDLINE
| ID: mdl-28906060
ABSTRACT
In the environment and during infection, the human intestinal pathogen Vibrio cholerae must overcome noxious compounds that damage the bacterial outer membrane. The El Tor and classical biotypes of O1 V. cholerae show striking differences in their resistance to membrane disrupting cationic antimicrobial peptides (CAMPs), such as polymyxins. The classical biotype is susceptible to CAMPs, but current pandemic El Tor biotype isolates gain CAMP resistance by altering the net charge of their cell surface through glycine modification of lipid A. Here we report a second lipid A modification mechanism that only functions in the V. cholerae El Tor biotype. We identify a functional EptA ortholog responsible for the transfer of the amino-residue phosphoethanolamine (pEtN) to the lipid A of V. cholerae El Tor that is not functional in the classical biotype. We previously reported that mildly acidic growth conditions (pH 5.8) downregulate expression of genes encoding the glycine modification machinery. In this report, growth at pH 5.8 increases expression of eptA with concomitant pEtN modification suggesting coordinated regulation of these LPS modification systems. Similarly, efficient pEtN lipid A substitution is seen in the absence of lipid A glycinylation. We further demonstrate EptA orthologs from non-cholerae Vibrio species are functional.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vibrio cholerae
/
Lipopolissacarídeos
/
Lipídeo A
Limite:
Humans
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos