PDBsum entry 1e8r

Hydrolase

PDB id: 1e8r

Contents

Protein chain

50 a.a. *

* Residue conservation analysis

PDB id:

1e8r

Name:

Hydrolase

Title:

Solution structure of type x cbd

Structure:

Endo-1,4-beta-xylanase. Chain: a. Fragment: type x cellulose binding domain (cbdx). Engineered: yes

Source:

Pseudomonas fluorescens. Organism_taxid: 294. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

5 models

Authors:

S.Raghothama,P.J.Simpson,H.J.Gilbert,M.P.Williamson

Key ref:

S.Raghothama et al. (2000). Solution structure of the CBM10 cellulose binding module from Pseudomonas xylanase A. Biochemistry, 39, 978-984. PubMed id: 10653641 DOI: 10.1021/bi992163+

Date:

28-Sep-00 Release date: 03-Oct-00

Supersedes:

1ct7

Protein chain

P14768  (XYNA_CELJU) -  Endo-1,4-beta-xylanase A from Cellvibrio japonicus (strain Ueda107)

Seq: 611 a.a.

Struc: 50 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

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: 10.1021/bi992163+

Biochemistry 39:978-984 (2000)

PubMed id: 10653641

Solution structure of the CBM10 cellulose binding module from Pseudomonas xylanase A.

S.Raghothama, P.J.Simpson, L.Szabó, T.Nagy, H.J.Gilbert, M.P.Williamson.

ABSTRACT

Plant cell wall hydrolases generally have a modular structure consisting of a catalytic domain linked to one or more noncatalytic carbohydrate-binding modules (CBMs), whose common function is to attach the enzyme to the polymeric substrate. Xylanase A from Pseudomonas fluorescens subsp. cellulosa (Pf Xyn10A) consists of a family 10 catalytic domain, an N-terminal family IIa cellulose-binding module, and an internal family 10 cellulose-binding module. The structure of the 45-residue family 10 CBM has been determined in solution using NMR. It consists of two antiparallel beta-sheets, one with two strands and one with three, with a short alpha-helix across one face of the three-stranded sheet. There is a high density of aromatic residues on one side of the protein, including three aromatic residues (Tyr8, Trp22, and Trp24), which are exposed and form a flat surface on one face, in a classical polysaccharide-binding arrangement. The fold is closely similar to that of the oligonucleotide/oligosaccharide-binding (OB) fold, but appears to have arisen by convergent evolution, because there is no sequence similarity, and the presumed binding sites are on different faces.