@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 {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 {1464,
	title = {PseG of pseudaminic acid biosynthesis - A UDP-sugar hydrolase as a masked glycosyltransferase},
	journal = {Journal of Biological Chemistry},
	volume = {281},
	number = {30},
	year = {2006},
	note = {ISI Document Delivery No.: 065VFTimes Cited: 12Cited Reference Count: 40Liu, Feng Tanner, Martin E.},
	month = {Jul},
	pages = {20902-20909},
	type = {Article},
	abstract = {The flagellin proteins in pathogenic bacteria such as Campylobacter jejuni and Helicobacter pylori are heavily glycosylated with the nine-carbon alpha-keto acid, pseudaminic acid. The presence of this posttranslational modification is absolutely required for assembly of functional flagella. Since motility is required for colonization, pseudaminic acid biosynthesis represents a virulence factor in these bacteria. Pseudaminic acid is generated from UDP-N-acetylglucosamine in five biosynthetic steps. The final step has been shown to involve the condensation of 2,4-diacetamido- 2,4,6-trideoxy-L-altrose ( 6-deoxy-AltdiNAc) with phosphoenolpyruvate as catalyzed by the enzyme pseudaminic acid synthase, NeuB3. The 6-deoxy-AltdiNAc used in this process is generated from its nucleotide-linked form, UDP-6-deoxy-AltdiNAc, by the action of a hydrolase that cleaves the glycosidic bond and releases UDP. This manuscript describes the first characterization of a UDP-6-deoxy-AltdiNAc hydrolase, namely PseG ( Cj1312) from C. jejuni. The activity of this enzyme is independent of the presence of divalent metal ions, and the values of the catalytic constants were found to be k(cat) = 27 s(-1) and K-m = 174 mu M. The enzyme was shown to hydrolyze the substrate with an overall inversion of stereochemistry at C-1 and to utilize a C-O bond cleavage mechanism during catalysis. These results, coupled with homology comparisons, suggest that the closest ancestors to the hydrolase are members of the metal-independent GT-B family of glycosyltransferases that include the enzyme MurG.},
	keywords = {CAMPYLOBACTER-JEJUNI, FLAGELLIN, FUNCTIONAL-CHARACTERIZATION, GLYCOPROTEINS, glycosylation, HELICOBACTER-PYLORI, IDENTIFICATION, MECHANISM, N-ACETYLGLUCOSAMINE 2-EPIMERASE, NUDIX HYDROLASES, SYNTHASE},
	isbn = {0021-9258},
	url = {<Go to ISI>://000239187300027},
	author = {Liu, F. and Tanner, M. E.}
}
@article {1127,
	title = {Structural and mechanistic analysis of sialic acid synthase NeuB from Neisseria meningitidis in complex with Mn2+ phosphoenolpyruvate, and N-acetylmannosaminitol},
	journal = {Journal of Biological Chemistry},
	volume = {280},
	number = {5},
	year = {2005},
	note = {ISI Document Delivery No.: 897DJTimes Cited: 19Cited Reference Count: 58},
	month = {Feb},
	pages = {3555-3563},
	type = {Article},
	abstract = {In Neisseria meningitidis and related bacterial pathogens, sialic acids play critical roles in mammalian cell immunity evasion and are synthesized by a conserved enzymatic pathway that includes sialic acid synthase (NeuB, SiaC, or SynC). NeuB catalyzes the condensation of phosphoenolpyruvate (PEP) and N-acetylmannosamine, directly forming N-acetylneuraminic acid (or sialic acid). In this paper we report the development of a coupled assay to monitor NeuB reaction kinetics and an O-18-labeling study that demonstrates the synthase operates via a C-O bond cleavage mechanism. We also report the first structure of a sialic acid synthase, that of NeuB, revealing a unique domain-swapped homodimer architecture consisting of a (beta/alpha)(8) barrel (TIM barrel)type fold at the N-terminal end and a domain with high sequence identity and structural similarity to the ice binding type III antifreeze proteins at the C-terminal end of the enzyme. We have determined the structures of NeuB in the malate-bound form and with bound PEP and the substrate analog N-acetylmannosaminitol to 1.9 and 2.2 Angstrom resolution, respectively. Typical of other TIM barrel proteins, the active site of NeuB is located in a cavity at the C-terminal end of the barrel; however, the positioning of the swapped antifreeze-like domain from the adjacent monomer provides key residues for hydrogen bonding with substrates in the active site of NeuB, a structural feature that leads to distinct modes of substrate binding from other PEP-utilizing enzymes that lack an analogous antifreeze-like domain. Our observation of a direct interaction between a highly ordered manganese and the N-acetylmannosaminitol in the NeuB active site also suggests an essential role for the ion as an electrophilic catalyst that activates the N-acetylmannosamine carbortyl to the addition of PEP.},
	keywords = {3-DEOXY-D-ARABINO-HEPTULOSONATE-7-PHOSPHATE SYNTHASE, 3-DEOXY-D-MANNO-OCTULOSONATE-8-PHOSPHATE SYNTHASE, ACETYLNEURAMINIC ACID, BISUBSTRATE, CAMPYLOBACTER-JEJUNI, CATALYTIC MECHANISM, CELL GLYCOSYLATION, ENZYMATIC SYNTHESIS, ESCHERICHIA-COLI, INHIBITOR, KDO8P SYNTHASE},
	isbn = {0021-9258},
	url = {<Go to ISI>://000226983900053},
	author = {Gunawan, J. and Simard, D. and Gilbert, M. and Lovering, A. L. and Wakarchuk, W. W. and Tanner, M. E. and Strynadka, N. C. J.}
}
