From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1dyp.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1dyp.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1dyp| PDB=1dyp | SCENE= }} | | {{STRUCTURE_1dyp| PDB=1dyp | SCENE= }} |
| | | | |
| - | '''1,3-ALPHA-1,4-BETA-D-GALACTOSE-4-SULFATE-3,6-ANHYDRO-D-GALACTOSE 4 GALACTOHYDROLASE'''
| + | ===1,3-ALPHA-1,4-BETA-D-GALACTOSE-4-SULFATE-3,6-ANHYDRO-D-GALACTOSE 4 GALACTOHYDROLASE=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | BACKGROUND: kappa-carrageenans are gel-forming, sulfated 1,3-alpha-1,4-beta-galactans from the cell walls of marine red algae. The kappa-carrageenase from the marine, gram-negative bacterium Pseudoalteromonas carrageenovora degrades kappa-carrageenan both in solution and in solid state by an endoprocessive mechanism. This beta-galactanase belongs to the clan-B of glycoside hydrolases. RESULTS: The structure of P. carrageenovora kappa-carrageenase has been solved to 1.54 A resolution by the multiwavelength anomalous diffraction (MAD) method, using a seleno-methionine-substituted form of the enzyme. The enzyme folds into a curved beta sandwich, with a tunnel-like active site cavity. Another remarkable characteristic is the presence of an arginine residue at subsite -1. CONCLUSIONS: The crystal structure of P. carrageenovora kappa-carrageenase is the first three-dimensional structure of a carrageenase. Its tunnel-shaped active site, the first to be reported for enzymes other than cellulases, suggests that such tunnels are associated with the degradation of solid polysaccharides. Clan-B glycoside hydrolases fall into two subgroups, one with catalytic machinery held by an ancestral beta bulge, and the other in which it is held by a regular beta strand. At subsite -1, all of these hydrolases exhibit an aromatic amino acid that interacts with the hexopyranose ring of the monosaccharide undergoing catalysis. In addition, in kappa-carrageenases, an arginine residue recognizes the sulfate-ester substituents of the beta-linked kappa-carrageenan monomers. It also appears that, in addition to the nucleophile and acid/base catalysts, two other amino acids are involved with the catalytic cycle, accelerating the deglycosylation step.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_11435116}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 11435116 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_11435116}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 28: |
Line 32: |
| | [[Category: Hydrolase]] | | [[Category: Hydrolase]] |
| | [[Category: Kappa-carrageenan double helix degradation]] | | [[Category: Kappa-carrageenan double helix degradation]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 14:26:35 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jun 30 23:49:13 2008'' |
Revision as of 20:49, 30 June 2008
Template:STRUCTURE 1dyp
1,3-ALPHA-1,4-BETA-D-GALACTOSE-4-SULFATE-3,6-ANHYDRO-D-GALACTOSE 4 GALACTOHYDROLASE
Template:ABSTRACT PUBMED 11435116
About this Structure
1DYP is a Single protein structure of sequence from Pseudoalteromonas carrageenovora. Full crystallographic information is available from OCA.
Reference
The kappa-carrageenase of P. carrageenovora features a tunnel-shaped active site: a novel insight in the evolution of Clan-B glycoside hydrolases., Michel G, Chantalat L, Duee E, Barbeyron T, Henrissat B, Kloareg B, Dideberg O, Structure. 2001 Jun;9(6):513-25. PMID:11435116
Page seeded by OCA on Mon Jun 30 23:49:13 2008
