1E0X

XYLANASE 10A FROM SREPTOMYCES LIVIDANS. XYLOBIOSYL-ENZYME INTERMEDIATE AT 1.65 A

Summary for 1E0X

• Entry DOI: 10.2210/pdb1e0x/pdb
• Related: 1E0V 1E0W 1XAS
• Descriptor: ENDO-1,4-BETA-XYLANASE A, beta-D-xylopyranose-(1-4)-2-deoxy-2-fluoro-alpha-D-xylopyranose, GLYCEROL, ... (4 entities in total)
• Functional Keywords: glycoside hydrolase family 10, hydrolase, xylan degradation, glycosyl-enzyme intermediate
• Biological source: STREPTOMYCES LIVIDANS
• Cellular location: Secreted: P26514
• Total number of polymer chains: 2
• Total formula weight: 69103.67

Authors

Ducros, V.,Charnock, S.J.,Derewenda, U.,Derewenda, Z.S.,Dauter, Z.,Dupont, C.,Shareck, F.,Morosoli, R.,Kluepfel, D.,Davies, G.J. (deposition date: 2000-04-10, release date: 2001-04-05, Last modification date: 2024-05-01)

Primary citation

Ducros, V.,Charnock, S.J.,Derewenda, U.,Derewenda, Z.S.,Dauter, Z.,Dupont, C.,Shareck, F.,Morosoli, R.,Kluepfel, D.,Davies, G.J.
Substrate Specificity in Glycoside Hydrolase Family 10. Structural and Kinetic Analysis of the Streptomyces Lividans Xylanase 10A
J.Biol.Chem., 275:23020-, 2000

PubMed Abstract: 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.

PubMed: 10930426
DOI: 10.1074/JBC.M000129200

Experimental method

X-RAY DIFFRACTION (1.65 Å)