Unknown

Dataset Information

0

The Brucella abortus cyclic beta-1,2-glucan virulence factor is substituted with O-ester-linked succinyl residues.


ABSTRACT: Brucella periplasmic cyclic beta-1,2-glucan plays an important role during bacterium-host interaction. Nuclear magnetic resonance spectrometry analysis, thin-layer chromatography, and DEAE-Sephadex chromatography were used to characterize Brucella abortus cyclic glucan. In the present study, we report that a fraction of B. abortus cyclic beta-1,2-glucan is substituted with succinyl residues, which confer anionic character on the cyclic beta-1,2-glucan. The oligosaccharide backbone is substituted at C-6 positions with an average of two succinyl residues per glucan molecule. This O-ester-linked succinyl residue is the only substituent of Brucella cyclic glucan. A B. abortus open reading frame (BAB1_1718) homologous to Rhodobacter sphaeroides glucan succinyltransferase (OpgC) was identified as the gene encoding the enzyme responsible for cyclic glucan modification. This gene was named cgm for cyclic glucan modifier and is highly conserved in Brucella melitensis and Brucella suis. Nucleotide sequencing revealed that B. abortus cgm consists of a 1,182-bp open reading frame coding for a predicted membrane protein of 393 amino acid residues (42.7 kDa) 39% identical to Rhodobacter sphaeroides succinyltransferase. cgm null mutants in B. abortus strains 2308 and S19 produced neutral glucans without succinyl residues, confirming the identity of this protein as the cyclic-glucan succinyltransferase enzyme. In this study, we demonstrate that succinyl substituents of cyclic beta-1,2-glucan of B. abortus are necessary for hypo-osmotic adaptation. On the other hand, intracellular multiplication and mouse spleen colonization are not affected in cgm mutants, indicating that cyclic-beta-1,2-glucan succinylation is not required for virulence and suggesting that no low-osmotic stress conditions must be overcome during infection.

SUBMITTER: Roset MS 

PROVIDER: S-EPMC1539967 | BioStudies | 2006-01-01

REPOSITORIES: biostudies

Similar Datasets

2004-01-01 | S-EPMC375185 | BioStudies
1998-01-01 | S-EPMC107446 | BioStudies
1000-01-01 | S-EPMC5072146 | BioStudies
2009-01-01 | S-EPMC2631987 | BioStudies
2015-01-01 | S-EPMC4403662 | BioStudies
2001-01-01 | S-EPMC98793 | BioStudies
2014-01-01 | S-EPMC4077732 | BioStudies
2007-01-01 | S-EPMC2034269 | BioStudies
1999-01-01 | S-EPMC103589 | BioStudies
2008-01-01 | S-EPMC2993879 | BioStudies