The adhesive and cohesive properties of a bacterial polysaccharide adhesin are modulated by a deacetylase.
Mol Microbiol
; 88(3): 486-500, 2013 May.
Article
in En
| MEDLINE
| ID: mdl-23517529
ABSTRACT
Bacterial exopolysaccharide synthesis is a prevalent and indispensible activity in many biological processes, including surface adhesion and biofilm formation. In Caulobacter crescentus, surface attachment and subsequent biofilm growth depend on the ability to synthesize an adhesive polar polysaccharide known as the holdfast. In this work, we show that polar polysaccharide synthesis is a conserved phenomenon among Alphaproteobacterial species closely related to C. crescentus. Among them, mutagenesis of Asticcacaulis biprosthecum showed that disruption of the hfsH gene, which encodes a putative polysaccharide deacetylase, leads to accumulation of holdfast in the culture supernatant. Examination of the hfsH deletion mutant in C. crescentus revealed that this strain synthesizes holdfast; however, like the A. biprosthecumâ
hfsH mutant, the holdfasts are shed into the medium and have decreased adhesiveness and cohesiveness. Site-directed mutagenesis at the predicted catalytic site of C. crescentusâ
HfsH phenocopied the ΔhfsH mutant and abolished the esterase activity of HfsH. In contrast, overexpression of HfsH increased cell adherence without increasing holdfast synthesis. We conclude that the polysaccharide deacetylase activity of HfsH is required for the adhesive and cohesive properties of the holdfast, as well as for the anchoring of the holdfast to the cell envelope.
Full text:
1
Database:
MEDLINE
Main subject:
Polysaccharides, Bacterial
/
Bacterial Adhesion
/
Caulobacter crescentus
/
Adhesins, Bacterial
/
Amidohydrolases
Language:
En
Journal:
Mol Microbiol
Journal subject:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Year:
2013
Type:
Article
Affiliation country:
United States