Cell-associated glucans of Burkholderia solanacearum and Xanthomonas campestris pv. citri: a new family of periplasmic glucans.
The cell-associated glucans produced by Burkholderia solanacearum and Xanthomonas campestris pv. citri were isolated by trichloroacetic acid treatment and gel permeation chromatography. The compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry, and high-performance anion-exchange chromatography. B. solanacearum synthesizes only a neutral cyclic glucan containing 13 glucose residues, and X. campestris pv. citri synthesizes a neutral cyclic glucan containing 16 glucose residues. The two glucans were further purified by high-performance anion-exchange chromatography. Methylation analysis revealed that these glucans are linked by 1,2-glycosidic bonds and one 1,6-glycosidic bond. Our 600-MHz homonuclear and 1H-13C heteronuclear nuclear magnetic resonance experiments revealed the presence of a single alpha-1,6-glycosidic linkage, whereas all other glucose residues are beta-1,2 linked. The presence of this single alpha-1,6 linkage, however, induces such structural constraints in these cyclic glucans that all individual glucose residues could be distinguished. The different anomeric proton signals allowed complete sequence-specific assignment of both glucans. The structural characteristics of these glucans contrast with those of the previously described osmoregulated periplasmic glucans.
Talaga
P
P
Laboratoire de Chimie Biologique, Centre National de la Recherche Scientifique UMR 11, Université des Sciences et Technologies de Lille, France.
Stahl
B
B
Wieruszeski
J M
JM
Hillenkamp
F
F
Tsuyumu
S
S
Lippens
G
G
Bohin
J P
JP
D019117:Burkholderia / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002462:Cell Membrane / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005936:Glucans / Q000737:chemistry* / Q000145:classification; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000145:classification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D016959:Xanthomonas campestris / Q000737:chemistry*
D005936:Glucans; D011135:Polysaccharides, Bacterial