2z48
From Proteopedia
(New page: 200px<br /><applet load="2z48" size="350" color="white" frame="true" align="right" spinBox="true" caption="2z48, resolution 1.70Å" /> '''Crystal Structure of...) |
|||
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | CEL-III is a Ca(2+)-dependent hemolytic lectin, isolated from the marine | + | CEL-III is a Ca(2+)-dependent hemolytic lectin, isolated from the marine invertebrate Cucumaria echinata. The three-dimensional structure of CEL-III/GalNAc and CEL-III/methyl alpha-galactoside complexes was solved by x-ray crystallographic analysis. In these complexes, five carbohydrate molecules were found to be bound to two carbohydrate-binding domains (domains 1 and 2) located in the N-terminal 2/3 portion of the polypeptide and that contained beta-trefoil folds similar to ricin B-chain. The 3-OH and 4-OH of bound carbohydrate molecules were coordinated with Ca(2+) located at the subdomains 1alpha, 1gamma, 2alpha, 2beta, and 2gamma, simultaneously forming hydrogen bond networks with nearby amino acid side chains, which is similar to carbohydrate binding in C-type lectins. The binding of carbohydrates was further stabilized by aromatic amino acid residues, such as tyrosine and tryptophan, through a stacking interaction with the hydrophobic face of carbohydrates. The importance of amino acid residues in the carbohydrate-binding sites was confirmed by the mutational analyses. The orientation of bound GalNAc and methyl alpha-galactoside was similar to the galactose moiety of lactose bound to the carbohydrate-binding site of the ricin B-chain, although the ricin B-chain does not require Ca(2+) ions for carbohydrate binding. The binding of the carbohydrates induced local structural changes in carbohydrate-binding sites in subdomains 2alpha and 2beta. Binding of GalNAc also induced a slight change in the main chain structure of domain 3, which could be related to the conformational change upon binding of specific carbohydrates to induce oligomerization of the protein. |
==About this Structure== | ==About this Structure== | ||
| Line 10: | Line 10: | ||
==Reference== | ==Reference== | ||
| - | C-type lectin-like carbohydrate | + | C-type lectin-like carbohydrate recognition of the hemolytic lectin CEL-III containing ricin-type -trefoil folds., Hatakeyama T, Unno H, Kouzuma Y, Uchida T, Eto S, Hidemura H, Kato N, Yonekura M, Kusunoki M, J Biol Chem. 2007 Dec 28;282(52):37826-35. Epub 2007 Oct 31. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17977832 17977832] |
[[Category: Cucumaria echinata]] | [[Category: Cucumaria echinata]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| Line 33: | Line 33: | ||
[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:00:05 2008'' |
Revision as of 17:00, 21 February 2008
|
Crystal Structure of Hemolytic Lectin CEL-III Complexed with GalNac
Overview
CEL-III is a Ca(2+)-dependent hemolytic lectin, isolated from the marine invertebrate Cucumaria echinata. The three-dimensional structure of CEL-III/GalNAc and CEL-III/methyl alpha-galactoside complexes was solved by x-ray crystallographic analysis. In these complexes, five carbohydrate molecules were found to be bound to two carbohydrate-binding domains (domains 1 and 2) located in the N-terminal 2/3 portion of the polypeptide and that contained beta-trefoil folds similar to ricin B-chain. The 3-OH and 4-OH of bound carbohydrate molecules were coordinated with Ca(2+) located at the subdomains 1alpha, 1gamma, 2alpha, 2beta, and 2gamma, simultaneously forming hydrogen bond networks with nearby amino acid side chains, which is similar to carbohydrate binding in C-type lectins. The binding of carbohydrates was further stabilized by aromatic amino acid residues, such as tyrosine and tryptophan, through a stacking interaction with the hydrophobic face of carbohydrates. The importance of amino acid residues in the carbohydrate-binding sites was confirmed by the mutational analyses. The orientation of bound GalNAc and methyl alpha-galactoside was similar to the galactose moiety of lactose bound to the carbohydrate-binding site of the ricin B-chain, although the ricin B-chain does not require Ca(2+) ions for carbohydrate binding. The binding of the carbohydrates induced local structural changes in carbohydrate-binding sites in subdomains 2alpha and 2beta. Binding of GalNAc also induced a slight change in the main chain structure of domain 3, which could be related to the conformational change upon binding of specific carbohydrates to induce oligomerization of the protein.
About this Structure
2Z48 is a Single protein structure of sequence from Cucumaria echinata with , , and as ligands. Full crystallographic information is available from OCA.
Reference
C-type lectin-like carbohydrate recognition of the hemolytic lectin CEL-III containing ricin-type -trefoil folds., Hatakeyama T, Unno H, Kouzuma Y, Uchida T, Eto S, Hidemura H, Kato N, Yonekura M, Kusunoki M, J Biol Chem. 2007 Dec 28;282(52):37826-35. Epub 2007 Oct 31. PMID:17977832
Page seeded by OCA on Thu Feb 21 19:00:05 2008
Categories: Cucumaria echinata | Single protein | Eto, S. | Hatakeyama, T. | Hidemura, H. | Kouzuma, Y. | Uchida, T. | Unno, H. | A2G | CA | MG | NGA | Calcium | Cel-iii | Galnac | Hemagglutination | Hemolysis | Lectin | Magnesium | Pore-forming | Toxin
