1aq0
From Proteopedia
| |||||||
| , resolution 2.0Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Activity: | Licheninase, with EC number 3.2.1.73 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
BARLEY 1,3-1,4-BETA-GLUCANASE IN MONOCLINIC SPACE GROUP
Overview
Both plants and bacteria produce enzymes capable of degrading the mixed-linked beta-glucan of the endosperm cell walls of cereal grains. The enzymes share the specificity for beta-1,4 glycosyl bonds of O-3-substituted glucose units in linear polysaccharides and a similar cleavage mechanism but are unrelated in sequence and tertiary structure. The three-dimensional structure of the 1,3-1, 4-beta-glucanase isoenzyme EII from barley was determined from monoclinic crystals at a resolution of 2.0 A. The protein is folded into a betaalpha8 barrel structure as has been shown previously (Varghese, J. N., Garrett, T. P. J., Colman, P. M., Chen, L., Hoj, P. B., and Fincher, G. B. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 2785-2789) by diffraction analysis at lower resolution of tetragonal crystals. It contains one N-glycosylation site which is described in detail with the sugar moieties attached to residue Asn190. The geometry and hydration of the barley 1,3-1,4-beta-glucanase is analyzed; a model beta-glucan fragment is placed into the binding site by molecular dynamics simulation, and the beta-glucan binding grooves of the plant and bacterial enzymes are compared. Their active sites are shown to have a small number of common features in generally dissimilar geometries that serve to explain both the identical substrate specificity and the observed differences in inhibitor binding.
About this Structure
1AQ0 is a Single protein structure of sequence from Hordeum vulgare. Full crystallographic information is available from OCA.
Reference
Crystal structure of barley 1,3-1,4-beta-glucanase at 2.0-A resolution and comparison with Bacillus 1,3-1,4-beta-glucanase., Muller JJ, Thomsen KK, Heinemann U, J Biol Chem. 1998 Feb 6;273(6):3438-46. PMID:9452466
Page seeded by OCA on Thu Mar 20 10:00:49 2008
