title: Fluorosugar chain termination agents as probes of the sequence specificity of a carbohydrate polymerase.
abstract: Naturally occurring carbohydrate polymers are ubiquitous. They are assembled by polymerizing glycosyltransferases, which can generate polysaccharide products with repeating sequence patterns. The fidelity of enzymes of this class is unknown. We report a method for testing the fidelity of carbohydrate polymerase pattern deposition: we synthesized fluorosugar donors and used them as chain termination agents. The requisite nucleotide fluorosugars could be produced from a single intermediate using the Jacobsen catalyst in a kinetically controlled separation of diastereomers. The resulting fluorosugar donors were used by the galactofuranosyltransferase GlfT2 from Mycobacterium tuberculosis, and the data indicate that this enzyme mediates the cell wall galactan production through a sequence-specific polymerization.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Brown
authors.forename: Max S
authors.initials: MS
authors.lastname: Rusek
authors.forename: Laura L
authors.initials: LL
authors.lastname: Kiessling
mesh_terms: D002240:Carbohydrate Sequence; D005700:Galactosyltransferases / Q000378:metabolism; D016695:Glycosyltransferases / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000201:enzymology; D058105:Polymerization; D011134:Polysaccharides / Q000096:biosynthesis*; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D011134:Polysaccharides; D016695:Glycosyltransferases; D005700:Galactosyltransferases