@article {2510,
	title = {The Engineering of Bacteria Bearing Azido-Pseudaminic Acid-Modified Flagella},
	journal = {Chembiochem},
	volume = {10},
	number = {8},
	year = {2009},
	note = {ISI Document Delivery No.: 452SMTimes Cited: 3Cited Reference Count: 24Liu, Feng Aubry, Annie J. Schoenhofen, Ian C. Logan, Susan M. Tanner, Martin E.},
	month = {May},
	pages = {1317-1320},
	type = {Article},
	keywords = {4, 6-DEHYDRATASE, azides, biosynthesis, C. jejuni, CAMPYLOBACTER-JEJUNI, cell surfaces, flagella, FUNCTIONAL-CHARACTERIZATION, HELICOBACTER-PYLORI, IDENTIFICATION, METABOLISM, PATHWAY, PROTEINS, PseB, reaction, Staudinger, UDP-N-ACETYLGLUCOSAMINE},
	isbn = {1439-4227},
	url = {<Go to ISI>://000266561500009},
	author = {Liu, F. and Aubry, A. J. and Schoenhofen, I. C. and Logan, S. M. and Tanner, M. E.}
}
@article {2140,
	title = {Mechanism and Active Site Residues of GDP-Fucose Synthase},
	journal = {Journal of the American Chemical Society},
	volume = {130},
	number = {51},
	year = {2008},
	note = {ISI Document Delivery No.: 406UOTimes Cited: 3Cited Reference Count: 37Lau, Stephen T. B. Tanner, Martin E.},
	month = {Dec},
	pages = {17593-17602},
	type = {Article},
	abstract = {L-Fucose, 6-deoxy-L-galactose, is a key component of many important glycoconjugates including the blood group antigens and the Lewis(x) ligands. The biosynthesis of GDP-L-fucose begins with the action of a dehydratase that converts GDP-D-mannose into GDP-4-keto-6-deoxy-mannose. The enzyme GDPfucose synthase, GFS, (also known as GDP-4-keto-6-deoxy-D-mannose epimerase/reductase, GMER) then converts GDP-4-keto-6-deoxy-D-mannose into GDP-L-fucose. The GFS reaction involves epimerizations at both C-3 {\textquoteright}{\textquoteright} and C-5 {\textquoteright}{\textquoteright} followed by an NADPH-dependent reduction of the carbonyl at C-4. This manuscript describes studies that elucidate the order of the epimerization steps and the roles of the active site acid/base residues responsible for the epimerizations. An active site mutant, Cys109Ser, produces GDP-6-deoxy-D-altrose as its major product indicating that C-3 {\textquoteright}{\textquoteright} epimerization occurs first and premature reduction of the GDP-4-keto-6-deoxy-D-altrose intermediate becomes competitive with GDP-L-fucose production. The same mutation results in the appearance of a kinetic isotope effect when [3 {\textquoteright}{\textquoteright}-H-2]-GDP-6-deoxy-4-keto-mannose is used as a substrate. This indicates that Cys109 is the base responsible for the deprotonation of the substrate at C-3 {\textquoteright}{\textquoteright}. The Cys109Ser mutant also catalyzes a rapid wash-in of solvent derived deuterium into the C-5 {\textquoteright}{\textquoteright} position of GDP-fucose in the presence of NADP(+). This confirms the order of epimerizations and the role of Cys109. Finally, the inactive His179Gln mutant readily catalyzes the wash-out of deuterium from the C-3 {\textquoteright}{\textquoteright} position of [3 {\textquoteright}{\textquoteright}-H-2]-GDP-6-deoxy-4-keto-mannose. Together these results strongly implicate an ordered sequence of epimerizations (C-3 {\textquoteright}{\textquoteright} followed by C-5 {\textquoteright}{\textquoteright}) and suggest that Cys109 acts as a base and His179 acts as an acid in both epimerization steps.},
	keywords = {6-DEHYDRATASE, ARABIDOPSIS-THALIANA, BIOLOGICAL FUNCTION, CATALYTIC MECHANISM, DTDP-GLUCOSE 4, ESCHERICHIA-COLI, GDP-4-KETO-6-DEOXY-D-MANNOSE EPIMERASE/REDUCTASE, HELICOBACTER-PYLORI, LEUKOCYTE ADHESION, MANNOSE 4, UDP-GALACTOSE 4-EPIMERASE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000263320600076},
	author = {Lau, S. T. B. and Tanner, M. E.}
}
@article {2193,
	title = {Mechanistic studies on PseB of pseudaminic acid biosynthesis: A UDP-N-acetylglucosamine 5-inverting 4,6-dehydratase},
	journal = {Bioorganic Chemistry},
	volume = {36},
	number = {4-6},
	year = {2008},
	note = {ISI Document Delivery No.: 386TPTimes Cited: 2Cited Reference Count: 33Morrison, James P. Schoenhofen, Ian C. Tanner, Martin E.},
	month = {Aug-Dec},
	pages = {312-320},
	type = {Article},
	abstract = {UDP-N-acetylglucosamine 5-inverting 4,6-dehydratase (PseB) is a unique sugar nucleotide dehydratase that inverts the C-5 {\textquoteright}{\textquoteright} stereocentre during conversion of UDP-N-acetylglucosamine to UDP-2-acetamido2,6-dideoxy-beta-L-arabino-hexos-4-ulose. PseB catalyzes the first step in the biosynthesis of pseudaminic acid, which is found as a post-translational modification on the flagellin of Campylobacter jejuni and Helicobacter pylori. PseB is proposed to use its tightly bound NADP(+) to oxidize UDP-GlcNAc at C-4 {\textquoteright}{\textquoteright}, enabling dehydration. The alpha,beta unsaturated ketone intermediate is then reduced by delivery of the hydride to C-6 {\textquoteright}{\textquoteright} and a proton to C-5 {\textquoteright}{\textquoteright}. Consistent with this, PseB from C. jejuni has been found to incorporate deuterium into the C-5 {\textquoteright}{\textquoteright} position of product during catalysis in D2O. Likewise, PseB catalyzes solvent isotope exchange into the H-5 {\textquoteright}{\textquoteright} position of product, and eliminates HF from the alternate Substrate, UDP-6-deoxy-6-fluoro-GlcNAc. Mutants of the putative catalytic residues aspartate 126, lysine 127 and tyrosine 135 have severely compromised dehydratase, solvent isotope exchange, and HF elimination activities. (C) 2008 Elsevier Inc. All rights reserved.},
	keywords = {6-DEHYDRATASE, Campylobacter jejuni, CAMPYLOBACTER-JEJUNI, dehydratase, DTDP-GLUCOSE 4, ENZYMES, FLAA1, FUNCTIONAL-CHARACTERIZATION, GDP-MANNOSE 4, HELICOBACTER-PYLORI, IDENTIFICATION, Inverting, MOTILITY, PATHWAY, PseB, Pseudaminic acid, UDP-N-acetylglucosamine 5-inverting 4},
	isbn = {0045-2068},
	url = {<Go to ISI>://000261905800019},
	author = {Morrison, J. P. and Schoenhofen, I. C. and Tanner, M. E.}
}
@article {966,
	title = {The mechanism of the reaction catalyzed by ADP-beta-L-glycero-D-manno-heptose 6-epimerase},
	journal = {Journal of the American Chemical Society},
	volume = {126},
	number = {29},
	year = {2004},
	note = {ISI Document Delivery No.: 840JTTimes Cited: 14Cited Reference Count: 24},
	month = {Jul},
	pages = {8878-8879},
	type = {Article},
	keywords = {4, 6-DEHYDRATASE, BACTERIA, D-MANNOHEPTOSE 6-EPIMERASE, EPIMERIZATION, ESCHERICHIA-COLI, GLUCOSE, INSIGHTS, NUCLEOTIDE-MODIFYING ENZYMES, OUTER-MEMBRANE, UDP-GALACTOSE 4-EPIMERASE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000222855300009},
	author = {Read, J. A. and Ahmed, R. A. and Morrison, J. P. and Coleman, W. G. and Tanner, M. E.}
}
@article {5208,
	title = {Sugar nucleotide-modifying enzymes},
	journal = {Current Organic Chemistry},
	volume = {5},
	number = {2},
	year = {2001},
	note = {ISI Document Delivery No.: 411FKTimes Cited: 12Cited Reference Count: 170},
	month = {Feb},
	pages = {169-192},
	type = {Review},
	abstract = {Sugar nucleotides serve as the activated forms of carbohydrates that are used in a wide range of biosynthetic pathways. Instead of building up the sugar nucleotide from the free sugar itself, nature often chooses to modify the "donor" portion of a pre-existing sugar nucleotide in a biosynthetically efficient manner. In doing so a rich variety of catalytic strategies are employed and this review focuses on recent mechanistic and structural studies of the sugar nucleotide-modifying enzymes. The review is organized around the types of reactions catalyzed and contains the following sections: Epimerases/Mutases/Decarboxylases, Eliminations and Substitutions, Oxidation and Reduction, and Substitutions on the Periphery of Sugar Nucleotides.},
	keywords = {4, 6-DEHYDRATASE, 6-DIDEOXYHEXOSES, ACETYLGLUCOSAMINE 2-EPIMERASE/N-ACETYLMANNOSAMINE, ACETYLNEURAMINIC ACID, biosynthesis, CYTIDINE DIPHOSPHATE 3, D-GLUCOSE, ESCHERICHIA-COLI K-12, FIRST 2, GDP-FUCOSE SYNTHETASE, KINASE, N-ACETYLGLUCOSAMINE, SITE-DIRECTED MUTAGENESIS, STEPS, UDP-GALACTOSE 4-EPIMERASE},
	isbn = {1385-2728},
	url = {<Go to ISI>://000167487300004},
	author = {Tanner, M. E.}
}
