PDBsum entry 3eng

Glycosyl hydrolase

PDB id: 3eng

Contents

Protein chain

213 a.a. *

Ligands

BGC-BGC

Waters ×145

* Residue conservation analysis

PDB id:

3eng

Name:

Glycosyl hydrolase

Title:

Structure of endoglucanase v cellobiose complex

Structure:

Endoglucanase v cellobiose complex. Chain: a. Fragment: catalytic core, residues 1 - 210. Ec: 3.2.1.4

Source:

Humicola insolens. Organism_taxid: 34413

Resolution:

1.90Å R-factor: 0.145

Authors:

G.J.Davies,M.Schulein

Key ref:

G.J.Davies et al. (1996). Structure determination and refinement of the Humicola insolens endoglucanase V at 1.5 A resolution. Acta Crystallogr D Biol Crystallogr, 52, 7. PubMed id: 15299721 DOI: 10.1107/S0907444995009280

Date:

17-Oct-96 Release date: 16-Jun-97

Protein chain

P43316  (GUN5_HUMIN) -  Endoglucanase-5 from Humicola insolens

Seq: 213 a.a.

Struc: 213 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: 10.1107/S0907444995009280

Acta Crystallogr D Biol Crystallogr 52:7 (1996)

PubMed id: 15299721

Structure determination and refinement of the Humicola insolens endoglucanase V at 1.5 A resolution.

G.J.Davies, G.Dodson, M.H.Moore, S.P.Tolley, Z.Dauter, K.S.Wilson, G.Rasmussen, M.Schülein.

ABSTRACT

The structure of the catalytic core of the endoglucanase V (EGV) from Humicola insolens has been determined by the method of multiple isomorphous replacement at 1.5 A resolution. The final model, refined with X-PLOR and PROLSQ, has a crystallographic R factor of 0.163 (R(free) = 0.240) with deviations from stereochemical target values of 0.012 A and 0.037 degrees for bonds and angles, respectively. The model was further refined with SHELXL, including anisotropic modelling of the protein-atom temperature factors, to give a final model with an R factor of 0.105 and an R(free) of 0.154. The initial isomorphous replacement electron-density map was poor and uninterpretable but was improved by the use of synchrotron data collected at a wavelength chosen so as to optimize the f" contribution of the anomalous scattering from the heavy atoms. The structure of H. insolens EGV consists of a six-stranded beta-barrel domain, similar to that found in a family of plant defence proteins, linked by a number of disulfide-bonded loop regions. A long open groove runs across the surface of the enzyme either side of which lie the catalytic aspartate residues. The 9 A separation of the catalytic carboxylate groups is consistent with the observation that EGV catalyzes the hydrolysis of the cellulose, beta(1-->4) links with inversion of configuration at the anomeric C1 atom. This structure is the first representative from the glycosyl hydrolase family 45.

Selected figure(s)

Figure 1.
Fig. 1. Sections of the electron- density maps of EGV corre- sponding to residues 90-94. The three maps shown are a) MIR map (convntional source), (b) MIR map (optimized A) and (c) the 1.5 A 2Fo-Fc map. The two MIR maps are contoured at a level of l cr and the 2Fo- F,. map at a level of 04 e A -3.

Figure 10.
Fig. 10. 2Fo- Fc electron density, contoured at 0.44 e A. -3, for the catalytic centr of EGV. The proposed proton donor, Asp 121, and the catalytic base, Aspl0, are labelled. Aspl21 is involved in a hydrogen-bonding network involving residues Thr6 and His119, as indicated.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (1996, 52, 7-0) copyright 1996.

Figures were selected by an automated process.