1xt3: Difference between revisions
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|PDB= 1xt3 |SIZE=350|CAPTION= <scene name='initialview01'>1xt3</scene>, resolution 2.4Å | |PDB= 1xt3 |SIZE=350|CAPTION= <scene name='initialview01'>1xt3</scene>, resolution 2.4Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=CIT:CITRIC ACID'>CIT</scene> | |LIGAND= <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=IDU:1,4-DIDEOXY-O2-SULFO-GLUCURONIC+ACID'>IDU</scene>, <scene name='pdbligand=SGN:N,O6-DISULFO-GLUCOSAMINE'>SGN</scene> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1xt3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xt3 OCA], [http://www.ebi.ac.uk/pdbsum/1xt3 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1xt3 RCSB]</span> | |||
}} | }} | ||
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[[Category: Wang, C H.]] | [[Category: Wang, C H.]] | ||
[[Category: Wu, W G.]] | [[Category: Wu, W G.]] | ||
[[Category: citrate]] | [[Category: citrate]] | ||
[[Category: ctx-3]] | [[Category: ctx-3]] | ||
[[Category: heparin]] | [[Category: heparin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:54:20 2008'' | ||
Revision as of 00:54, 31 March 2008
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| , resolution 2.4Å | |||||||
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| Ligands: | , , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure Basis of Venom Citrate-Dependent Heparin Sulfate-Mediated Cell Surface Retention of Cobra Cardiotoxin A3
OverviewOverview
Anionic citrate is a major component of venom, but the role of venom citrate in toxicity other than its inhibitory effect on the cation-dependent action of venom toxins is poorly understood. By immobilizing Chinese hamster ovary cells in microcapillary tubes and heparin on sensor chips, we demonstrated that heparan sulfate-mediated cell retention of the major cardiotoxin (CTX) from the Taiwan cobra, CTX A3, near membrane surfaces is citrate-dependent. X-ray determination of a CTX A3-heparin hexasaccharide complex structure at 2.4 A resolution revealed a molecular mechanism for toxin retention in which heparin-induced conformational changes of CTX A3 lead to citrate-mediated dimerization. A citrate ion bound to Lys-23 and Lys-31 near the tip of loop II stabilizes hydrophobic contact of the CTX A3 homodimer at the functionally important loop I and II regions. Additionally, the heparin hexasaccharide interacts with five CTX A3 molecules in the crystal structure, providing another mechanism whereby the toxin establishes a complex network of interactions that result in a strong interaction with cell surfaces presenting heparan sulfate. Our results suggest a novel role for venom citrate in biological activity and reveal a structural model that explains cell retention of cobra CTX A3 through heparan sulfate-CTX interactions.
About this StructureAbout this Structure
1XT3 is a Single protein structure of sequence from Naja atra. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of citrate-dependent and heparan sulfate-mediated cell surface retention of cobra cardiotoxin A3., Lee SC, Guan HH, Wang CH, Huang WN, Tjong SC, Chen CJ, Wu WG, J Biol Chem. 2005 Mar 11;280(10):9567-77. Epub 2004 Dec 6. PMID:15590643
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