Substrate Specificity in Glycoside Hydrolase Family 10. Structural and Kinetic Analysis of the Streptomyces Lividans Xylanase 10ADucros, V., Charnock, S.J., Derewenda, U., Derewenda, Z.S., Dauter, Z., Dupont, C., Shareck, F., Morosoli, R., Kluepfel, D., Davies, G.J.
(2000) J.Biol.Chem. 275: 23020
- PubMed: 10930426
- Primary Citation of Related Structures:  1E0V, 1E0X
- PubMed Abstract:
- Substrate Specificity in Glycoside Hydrolase Family 10. Tyrosine 87 and Leucine 314 Play a Pivotal Role in Discriminating between Glucose and Xylose Binding in the Proximal Active Site of Pseudomonas Cellulosa Xylanase 10A.
Andrews, S.R.,Charnock, S.J.,Lakey, J.H.,Davies, G.J.,Claeyssens, M.,Nerinckx, W.,Underwood, M.,Sinnott, M.L.,Warren, R.A.,Gilbert, H.J.
(2000) J.Biol.Chem. 275: 23027
- Crystal Structure, at 2.6 A Resolution, of the Streptomyces Lividans Xylanase A, a Member of the F Family of B-1,4-D-Glycanases
Derewenda, U.,Swenson, L.,Green, R.,Wei, Y.,Morosoli, R.,Shareck, F.,Kluepfel, D.,Derewenda, Z.S.
(1994) J.Biol.Chem. 269: 20811
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 Xyl ...
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.
Department of Chemistry, Structural Biology Laboratory, University of York, Heslington, York YO10 5DD, United Kingdom.