1ojk: Difference between revisions
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==Overview== | ==Overview== | ||
The formation of glycoconjugates and oligosaccharides remains one of the, most challenging chemical syntheses. Chemo-enzymatic routes using, retaining glycosidases have been successfully harnessed but require tight, kinetic or thermodynamic control. "Glycosynthases," specifically, engineered glycosidases that catalyze the formation of glycosidic bonds, from glycosyl donor and acceptor alcohol, are an emerging range of, synthetic tools in which catalytic nucleophile mutants are harnessed, together with glycosyl fluoride donors to generate powerful and versatile, catalysts. Here we present the structural and kinetic dissection of the, Humicola insolens Cel7B glycosynthases in which the nucleophile of the, wild-type enzyme is mutated to alanine and serine (E197A and E197S). 3-D, structures . | The formation of glycoconjugates and oligosaccharides remains one of the, most challenging chemical syntheses. Chemo-enzymatic routes using, retaining glycosidases have been successfully harnessed but require tight, kinetic or thermodynamic control. "Glycosynthases," specifically, engineered glycosidases that catalyze the formation of glycosidic bonds, from glycosyl donor and acceptor alcohol, are an emerging range of, synthetic tools in which catalytic nucleophile mutants are harnessed, together with glycosyl fluoride donors to generate powerful and versatile, catalysts. Here we present the structural and kinetic dissection of the, Humicola insolens Cel7B glycosynthases in which the nucleophile of the, wild-type enzyme is mutated to alanine and serine (E197A and E197S). 3-D, structures reveal the acceptor and donor subsites and the basis for, substrate inhibition. Kinetic analysis shows that the E197S mutant is, considerably more active than the corresponding alanine mutant due to a, 40-fold increase in k(cat). | ||
==About this Structure== | ==About this Structure== | ||
1OJK is a | 1OJK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Humicola_insolens Humicola insolens] with NAG and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cellulase Cellulase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.4 3.2.1.4] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1OJK OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: hydrolase]] | [[Category: hydrolase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:58:08 2007'' | ||
