@article {1436,
	title = {Glycosynthase-based synthesis of xylo-oligosaccharides using an engineered retaining xylanase from Cellulomonas fimi},
	journal = {Organic \& Biomolecular Chemistry},
	volume = {4},
	number = {10},
	year = {2006},
	note = {ISI Document Delivery No.: 041NHTimes Cited: 20Cited Reference Count: 39},
	pages = {2025-2032},
	type = {Article},
	abstract = {Glycosynthases are synthetic enzymes derived from retaining glycosidases in which the catalytic nucleophile has been replaced. The mutation allows irreversible glycosylation of sugar acceptors using glycosyl fluoride donors to afford oligosaccharides without any enzymatic hydrolysis. Glycosynthase technology has proven fruitful for the facile synthesis of useful oligosaccharides, therefore the expansion of the glycosynthase repertoire is of the utmost importance. Herein, we describe for the first time a glycosynthase, derived from a retaining xylanase, that synthesizes a range of xylo-oligosaccharides. The catalytic domain of the retaining endo-1,4-beta-xylanase from Cellulomonas fimi (CFXcd) was successfully converted to the corresponding glycosynthase by mutation of the catalytic nucleophile to a glycine residue. The mutant enzyme (CFXcd-E235G) was found to catalyze the transfer of a xylobiosyl moiety from alpha-xylobiosyl fluoride to either p-nitrophenyl beta-xylobioside or benzylthio beta-xylobioside to afford oligosaccharides ranging in length from tetra- to dodecasaccharides. These products were purified by high performance liquid chromatography in greater than 60\% combined yield. H-1 and C-13 NMR spectroscopic analyses of the isolated p-nitrophenyl xylotetraoside and p-nitrophenyl xylohexaoside revealed that CFXcd-E235G catalyzes both the regio- and stereo-selective synthesis of xylo-oligosaccharides containing, exclusively, beta-(1 {\textendash}> 4) linkages.},
	keywords = {4-GLYCANASE, BETA-1, DIRECTED EVOLUTION, EFFICIENT SYNTHESIS, ENZYMATIC-SYNTHESIS, GLYCOSIDASES, MASS-SPECTROMETRY, SPECIFICITY, SUBSTRATE, TRANSGLYCOSYLATION, XYLOOLIGOSACCHARIDES},
	isbn = {1477-0520},
	url = {<Go to ISI>://000237462400022},
	author = {Kim, Y. W. and Fox, D. T. and Hekmat, O. and Kantner, T. and McIntosh, L. P. and Warren, R. A. J. and Withers, S. G.}
}
@article {4856,
	title = {Binding site analysis of cellulose binding domain CBDN1 from endoglucanse C of Cellulomonas fimi by site-directed mutagenesis},
	journal = {Biochemistry},
	volume = {39},
	number = {30},
	year = {2000},
	note = {ISI Document Delivery No.: 339RJTimes Cited: 17Cited Reference Count: 59},
	month = {Aug},
	pages = {8844-8852},
	type = {Article},
	abstract = {Endoglucanase C (CenC), a beta 1,4 glucanase from the soil bacterium Cellulomonas fimi, binds to amorphous cellulose via two homologous cellulose binding domains, termed CBDN1 and CBDN2. in this work, the contributions of 10 amino acids within the binding cleft of CBDN1 were evaluated by single site-directed mutations to alanine residues. Each isolated domain containing a single mutation was analyzed for binding to an insoluble amorphous preparation of cellulose, phosphoric acid swollen Avicel (PASA), and to a soluble glucopyranoside polymer, barley beta-glucan. The effect of any given mutation on CBD binding was similar for both substrates, suggesting that the mechanism of binding to soluble and insoluble substrates is the same. Tyrosines 19 and 85 were essential for tight binding by CBDN1 as their replacement by alanine results in affinity decrements of approximately 100-fold on PASA, barley beta-glucan, and soluble cellooligosaccharides. The tertiary structures of unbound Y19A and Y85A were assessed by heteronuclear single quantum coherence (HSQC) spectroscopy. These studies indicated that the structures of both mutants were perturbed but that all perturbations are very near to the site of mutation.},
	keywords = {4-GLUCANASE CENC, BETA-1, ESCHERICHIA-COLI, LIGAND-BINDING, LIMITED PROTEOLYSIS, MECHANISM, N-ACETYLGLUCOSAMINE, NUCLEAR-MAGNETIC-RESONANCE, REESEI CELLOBIOHYDROLASE-I, TRICHODERMA-REESEI, TRYPTOPHAN RESIDUES},
	isbn = {0006-2960},
	url = {<Go to ISI>://000088491500018},
	author = {Kormos, J. and Johnson, P. E. and Brun, E. and Tomme, P. and McIntosh, L. P. and Haynes, C. A. and Kilburn, D. G.}
}
