Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Brucella abortus [ICD11:
XN7A8 
]
NCBI PubMed ID: 19074375Publication DOI: 10.1128/JB.01108-08Journal NLM ID: 2985120RPublisher: American Society for Microbiology
Correspondence: rugalde
iib.unsam.edu.ar
Institutions: Instituto de Investigaciones Biotecnologicas, Universidad Nacional de San Martin, Buenos Aires, Argentina
Cyclic β-1,2-glucans (CβG) are periplasmic homopolysaccharides that have been shown to play an important role in several symbiotic and pathogenic relationships. Cyclic β-1,2-glucan synthase (Cgs), the enzyme responsible for the synthesis of CβG, is an integral membrane polyfunctional protein that catalyzes the four enzymatic activities (initiation, elongation, phosphorolysis, and cyclization) required for the synthesis of CβG. Recently, we have identified the glycosyltransferase and the β-1,2-glucooligosaccharide phosphorylase domains of Brucella abortus Cgs. In this study, we performed large-scale linker-scanning mutagenesis to gain further insight into the functional domains of Cgs. This analysis allowed us to construct a functional map of the enzyme and led to the identification of the minimal region required for the catalysis of initiation and elongation reactions. In addition, we identified the Cgs region (residues 991 to 1544) as being the protein domain required for cyclization and demonstrated that upon cyclization and releasing of the CβG, one or more glucose residues remain attached to the protein intermediate that serves as a primer for the next round of CβG synthesis. Finally, our results indicate that the overall control of the degree of polymerization of CβG is the result of a balance between elongation, phosphorolysis, and cyclization reactions
Brucella abortus, Glucosyltransferases, beta-glucans
Structure type: cyclic polymer repeating unit ; n=17-25
Location inside paper: p.1230
Trivial name: cyclosophoran, cyclic β-1,2-glucan, cyclic b-glucan
Compound class: EPS, glucan, cyclic b-glucan
Contained glycoepitopes: IEDB_140628,IEDB_142488,IEDB_146664,IEDB_983931,SB_192
Methods: Western blotting, genetic methods, biochemical methods
Biological activity: virulence factor; biological activity data
Enzymes that release or process the structure: cyclic β-1,2-glucan synthase
Biosynthesis and genetic data: genetic data
Comments, role: cyclic b-1,2-backbones substituted with sn-1-phosphoglycerol, succinic acid, methylmalonic acid or combination of them
NCBI Taxonomy refs (TaxIDs): 235Reference(s) to other database(s): GTC:G21553SY, GlycomeDB:
25048
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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