2exo: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2exo.jpg|left|200px]] | [[Image:2exo.jpg|left|200px]] | ||
'''CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF THE BETA-1,4-GLYCANASE CEX FROM CELLULOMONAS FIMI''' | {{Structure | ||
|PDB= 2exo |SIZE=350|CAPTION= <scene name='initialview01'>2exo</scene>, resolution 1.8Å | |||
|SITE= | |||
|LIGAND= | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Cellulose_1,4-beta-cellobiosidase Cellulose 1,4-beta-cellobiosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.91 3.2.1.91] | |||
|GENE= | |||
}} | |||
'''CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF THE BETA-1,4-GLYCANASE CEX FROM CELLULOMONAS FIMI''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
2EXO is a [ | 2EXO is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Cellulomonas_fimi Cellulomonas fimi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EXO OCA]. | ||
==Reference== | ==Reference== | ||
Crystal structure of the catalytic domain of the beta-1,4-glycanase cex from Cellulomonas fimi., White A, Withers SG, Gilkes NR, Rose DR, Biochemistry. 1994 Oct 25;33(42):12546-52. PMID:[http:// | Crystal structure of the catalytic domain of the beta-1,4-glycanase cex from Cellulomonas fimi., White A, Withers SG, Gilkes NR, Rose DR, Biochemistry. 1994 Oct 25;33(42):12546-52. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/7918478 7918478] | ||
[[Category: Cellulomonas fimi]] | [[Category: Cellulomonas fimi]] | ||
[[Category: Cellulose 1,4-beta-cellobiosidase]] | [[Category: Cellulose 1,4-beta-cellobiosidase]] | ||
| Line 20: | Line 29: | ||
[[Category: hydrolase (o-glycosyl)]] | [[Category: hydrolase (o-glycosyl)]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 16:45:41 2008'' | ||
Revision as of 14:45, 20 March 2008
| |||||||||||||
| 2exo, resolution 1.8Å | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Activity: | Cellulose 1,4-beta-cellobiosidase, with EC number 3.2.1.91 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF THE BETA-1,4-GLYCANASE CEX FROM CELLULOMONAS FIMI
Overview
beta-1,4-Glycanases, principally cellulases and xylanases, are responsible for the hydrolysis of plant biomass. The bifunctional beta-1,4-xylanase/glucanase Cex from the bacterium Cellulomonas fimi, one of a large family of cellulases/xylanases, depolymerizes oligosaccharides and releases a disaccharide unit from the substrate nonreducing end. Hydrolysis occurs with net retention of the anomeric configuration of the sugar through a double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. The active site nucleophile, Glu233, has been unambiguously identified by trapping of such an intermediate [Tull et al. (1991) J. Biol. Chem. 266, 15621-15625] and the acid/base catalyst, Glu127, by detailed kinetic analysis of mutants [MacLeod et al. (1994) Biochemistry 33, 6371-6376]. However, little is known about the enzyme's overall folding and its active site architecture. We report here the high-resolution crystal structure of the catalytic domain of Cex. The atomic structure refinement results in a model that includes 2400 protein atoms and 45 water molecules, with an R-factor of 0.217 for data extending to 1.8-A resolution. The protein forms an eight-parallel-stranded alpha/beta-barrel, which is a novel folding pattern for a microbial beta-glycanase. The active site, inferred from the location of Glu233, Glu127, and other conserved residues, is an open cleft on the carboxy-terminal end of the alpha/beta-barrel. An extensive hydrogen-bonding network stabilizes the ionization states of the key residues; in particular, the Asp235-His205-Glu233 hydrogen-bonding network may play a role in modulating the ionization state of Glu233 and in controlling local charge balance during the reaction.
About this Structure
2EXO is a Single protein structure of sequence from Cellulomonas fimi. Full crystallographic information is available from OCA.
Reference
Crystal structure of the catalytic domain of the beta-1,4-glycanase cex from Cellulomonas fimi., White A, Withers SG, Gilkes NR, Rose DR, Biochemistry. 1994 Oct 25;33(42):12546-52. PMID:7918478
Page seeded by OCA on Thu Mar 20 16:45:41 2008
