PDBsum entry: 1j84

Hydrolase

PDB id: 1j84

Contents

Protein chain

179 a.a. *

Ligands

BGC-BGC-BGC-BGC

Metals

_CA

Waters ×156

* Residue conservation analysis

PDB id:

1j84

Name:

Hydrolase

Title:

Structure of fam17 carbohydrate binding module from clostridium cellulovorans with bound cellotetraose

Structure:

Endo-1,4-beta glucanase engf. Chain: a. Engineered: yes

Source:

Clostridium cellulovorans. Organism_taxid: 1493. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.02Å R-factor: 0.225 R-free: 0.264

Authors:

V.Notenboom,A.B.Boraston,P.Chiu,A.C.J.Freelove,D.G.Kilburn, D.R.Rose

Key ref:

V.Notenboom et al. (2001). Recognition of cello-oligosaccharides by a family 17 carbohydrate-binding module: an X-ray crystallographic, thermodynamic and mutagenic study. J Mol Biol, 314, 797-806. PubMed id: 11733998 DOI: 10.1006/jmbi.2001.5153

Date:

20-May-01 Release date: 12-Dec-01

Protein chain

P94622  (P94622_CLOCL) -  Endo-1,4-beta glucanase EngF

Seq: 557 a.a.

Struc: 179 a.a.

Enzyme reactions

• Enzyme class: E.C.3.2.1.4 - Cellulase.
• Reaction: Endohydrolysis of 1,4-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans.

DOI no: 10.1006/jmbi.2001.5153

J Mol Biol 314:797-806 (2001)

PubMed id: 11733998

Recognition of cello-oligosaccharides by a family 17 carbohydrate-binding module: an X-ray crystallographic, thermodynamic and mutagenic study.

V.Notenboom, A.B.Boraston, P.Chiu, A.C.Freelove, D.G.Kilburn, D.R.Rose.

ABSTRACT

The crystal structure of the Clostridium cellulovorans carbohydrate-binding module (CBM) belonging to family 17 has been solved to 1.7 A resolution by multiple anomalous dispersion methods. CBM17 binds to non-crystalline cellulose and soluble beta-1,4-glucans, with a minimal binding requirement of cellotriose and optimal affinity for cellohexaose. The crystal structure of CBM17 complexed with cellotetraose solved at 2.0 A resolution revealed that binding occurs in a cleft on the surface of the molecule involving two tryptophan residues and several charged amino acids. Thermodynamic binding studies and alanine scanning mutagenesis in combination with the cellotetraose complex structure allowed the mapping of the CBM17 binding cleft. In contrast to the binding groove characteristic of family 4 CBMs, family 17 CBMs appear to have a very shallow binding cleft that may be more accessible to cellulose chains in non-crystalline cellulose than the deeper binding clefts of family 4 CBMs. The structural differences in these two modules may reflect non-overlapping binding niches on cellulose surfaces.

Selected figure(s)

Figure 1.
Figure 1. Ribbon representation of the 3D structure of CBM17; depicted in gold is the cellotetraose moiety as observed in the crystal structure. Residues that were predicted to form interactions with the ligand by alanine scanning mutagenesis are shown as ball and stick.

Figure 2.
Figure 2. Cartoon representation of ligand interactions in the binding cleft of CBM17. Green broken lines depict hydrogen bonds (lengths in Å). Orange flares around atoms represent hydrophobic contacts between ligand and protein.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2001, 314, 797-806) copyright 2001.

Figures were selected by an automated process.