1e0v: Difference between revisions
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==Overview== | ==Overview== | ||
Endoxylanases are a group of enzymes that hydrolyze the beta-1, 4-linked | Endoxylanases are a group of enzymes that hydrolyze the beta-1, 4-linked xylose backbone of xylans. They are predominantly found in two discrete sequence families known as glycoside hydrolase families 10 and 11. The Streptomyces lividans xylanase Xyl10A is a family 10 enzyme, the native structure of which has previously been determined by x-ray crystallography at a 2.6 A resolution (Derewenda, U., Swenson, L., Green, R., Wei, Y., Morosoli, R., Shareck, F., Kluepfel, D., and Derewenda, Z. S. (1994) J. Biol. Chem. 269, 20811-20814). Here, we report the native structure of Xyl10A refined at a resolution of 1.2 A, which reveals many features such as the rare occurrence of a discretely disordered disulfide bond between residues Cys-168 and Cys-201. In order to investigate substrate binding and specificity in glycoside hydrolase family 10, the covalent xylobiosyl enzyme and the covalent cellobiosyl enzyme intermediates of Xyl10A were trapped through the use of appropriate 2-fluoroglycosides. The alpha-linked intermediate with the nucleophile, Glu-236, is in a (4)C(1) chair conformation as previously observed in the family 10 enzyme Cex from Cellulomonas fimi (Notenboom, V., Birsan, C., Warren, R. A. J., Withers, S. G., and Rose, D. R. (1998) Biochemistry 37, 4751-4758). The different interactions of Xyl10A with the xylobiosyl and cellobiosyl moieties, notably conformational changes in the -2 and -1 subsites, together with the observed kinetics on a range of aryl glycosides, shed new light on substrate specificity in glycoside hydrolase family 10. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Streptomyces lividans]] | [[Category: Streptomyces lividans]] | ||
[[Category: Charnock, S | [[Category: Charnock, S J.]] | ||
[[Category: Dauter, Z.]] | [[Category: Dauter, Z.]] | ||
[[Category: Davies, G | [[Category: Davies, G J.]] | ||
[[Category: Derewenda, U.]] | [[Category: Derewenda, U.]] | ||
[[Category: Derewenda, Z | [[Category: Derewenda, Z S.]] | ||
[[Category: Ducros, V.]] | [[Category: Ducros, V.]] | ||
[[Category: Dupont, C.]] | [[Category: Dupont, C.]] | ||
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[[Category: xylanase]] | [[Category: xylanase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:22:33 2008'' | ||
Revision as of 13:22, 21 February 2008
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XYLANASE 10A FROM SREPTOMYCES LIVIDANS. CELLOBIOSYL-ENZYME INTERMEDIATE AT 1.7 A
OverviewOverview
Endoxylanases are a group of enzymes that hydrolyze the beta-1, 4-linked xylose backbone of xylans. They are predominantly found in two discrete sequence families known as glycoside hydrolase families 10 and 11. The Streptomyces lividans xylanase Xyl10A is a family 10 enzyme, the native structure of which has previously been determined by x-ray crystallography at a 2.6 A resolution (Derewenda, U., Swenson, L., Green, R., Wei, Y., Morosoli, R., Shareck, F., Kluepfel, D., and Derewenda, Z. S. (1994) J. Biol. Chem. 269, 20811-20814). Here, we report the native structure of Xyl10A refined at a resolution of 1.2 A, which reveals many features such as the rare occurrence of a discretely disordered disulfide bond between residues Cys-168 and Cys-201. In order to investigate substrate binding and specificity in glycoside hydrolase family 10, the covalent xylobiosyl enzyme and the covalent cellobiosyl enzyme intermediates of Xyl10A were trapped through the use of appropriate 2-fluoroglycosides. The alpha-linked intermediate with the nucleophile, Glu-236, is in a (4)C(1) chair conformation as previously observed in the family 10 enzyme Cex from Cellulomonas fimi (Notenboom, V., Birsan, C., Warren, R. A. J., Withers, S. G., and Rose, D. R. (1998) Biochemistry 37, 4751-4758). The different interactions of Xyl10A with the xylobiosyl and cellobiosyl moieties, notably conformational changes in the -2 and -1 subsites, together with the observed kinetics on a range of aryl glycosides, shed new light on substrate specificity in glycoside hydrolase family 10.
About this StructureAbout this Structure
1E0V is a Single protein structure of sequence from Streptomyces lividans with as ligand. Active as Endo-1,4-beta-xylanase, with EC number 3.2.1.8 Known structural/functional Sites: , and . Full crystallographic information is available from OCA.
ReferenceReference
Substrate specificity in glycoside hydrolase family 10. Structural and kinetic analysis of the Streptomyces lividans xylanase 10A., Ducros V, Charnock SJ, Derewenda U, Derewenda ZS, Dauter Z, Dupont C, Shareck F, Morosoli R, Kluepfel D, Davies GJ, J Biol Chem. 2000 Jul 28;275(30):23020-6. PMID:10930426
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