4ENG

STRUCTURE OF ENDOGLUCANASE V CELLOHEXAOSE COMPLEX

Summary for 4ENG

• Entry DOI: 10.2210/pdb4eng/pdb
• Related PRD ID: PRD_900014
• Descriptor: ENDOGLUCANASE V CELLOHEXAOSE COMPLEX, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• Functional Keywords: hydrolase, endoglucanase, glycosyl hydrolase
• Biological source: Humicola insolens
• Total number of polymer chains: 1
• Total formula weight: 23553.86

Authors

Davies, G.J.,Schulein, M. (deposition date: 1996-10-17, release date: 1997-06-16, Last modification date: 2023-08-09)

Primary citation

Davies, G.J.,Dodson, G.,Moore, M.H.,Tolley, S.P.,Dauter, Z.,Wilson, K.S.,Rasmussen, G.,Schulein, M.
Structure determination and refinement of the Humicola insolens endoglucanase V at 1.5 A resolution.
Acta Crystallogr.,Sect.D, 52:7-17, 1996

PubMed 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.

PubMed: 15299721
DOI: 10.1107/S0907444995009280

Experimental method

X-RAY DIFFRACTION (1.9 Å)