PDBsum entry 1e0x

Hydrolase

PDB id: 1e0x

Contents

Protein chains

310 a.a. *

Ligands

X2F-XYP ×2

GOL ×3

Waters ×717

* Residue conservation analysis

PDB id:

1e0x

Name:

Hydrolase

Title:

Xylanase 10a from sreptomyces lividans. Xylobiosyl-enzyme intermediate at 1.65 a

Structure:

Endo-1,4-beta-xylanase a. Chain: a, b. Fragment: catalytic module, residues 32-450. Synonym: xylanase a, 1,4-beta-d-xylan xylanohydrolase a. Engineered: yes. Other_details: glycosyl enxyme intermediate. Covalent link between glu 236 and the substrate

Source:

Streptomyces lividans. Organism_taxid: 1916. Expressed in: streptomyces lividans. Expression_system_taxid: 1916.

Resolution:

1.65Å R-factor: 0.126 R-free: 0.162

Authors:

V.Ducros,S.J.Charnock,U.Derewenda,Z.S.Derewenda,Z.Dauter,C.Dupont, F.Shareck,R.Morosoli,D.Kluepfel,G.J.Davies

Key ref:

V.Ducros et al. (2000). Substrate specificity in glycoside hydrolase family 10. Structural and kinetic analysis of the Streptomyces lividans xylanase 10A. J Biol Chem, 275, 23020-23026. PubMed id: 10930426 DOI: 10.1074/jbc.275.30.23020

Date:

10-Apr-00 Release date: 05-Apr-01

Protein chains

P26514  (XYNA_STRLI) -  Endo-1,4-beta-xylanase A from Streptomyces lividans

Seq: 477 a.a.

Struc: 310 a.a.

Enzyme reactions

• Enzyme class: E.C.3.2.1.8 - endo-1,4-beta-xylanase.
• Reaction: Endohydrolysis of 1,4-beta-D-xylosidic linkages in xylans.

DOI no: 10.1074/jbc.275.30.23020

J Biol Chem 275:23020-23026 (2000)

PubMed id: 10930426

Substrate specificity in glycoside hydrolase family 10. Structural and kinetic analysis of the Streptomyces lividans xylanase 10A.

V.Ducros, S.J.Charnock, U.Derewenda, Z.S.Derewenda, Z.Dauter, C.Dupont, F.Shareck, R.Morosoli, D.Kluepfel, G.J.Davies.

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.

Selected figure(s)

Figure 4.
Fig. 4. Double displacement reaction mechanism as applied to the S. lividans Xyl10A.

Figure 6.
Fig. 6. Schematic diagram of the protein-ligand interactions for the 2F-xylobiosyl enzyme intermediate of Xyl10A. Distances less than 3.2 Å are indicated.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2000, 275, 23020-23026) copyright 2000.

Figures were selected by an automated process.