1dq2: Difference between revisions
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[[Image:1dq2.jpg|left|200px]] | [[Image:1dq2.jpg|left|200px]] | ||
'''Unlocked metal-free concanavalin A''' | {{Structure | ||
|PDB= 1dq2 |SIZE=350|CAPTION= <scene name='initialview01'>1dq2</scene>, resolution 2.05Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ACY:ACETIC ACID'>ACY</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''Unlocked metal-free concanavalin A''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1DQ2 is a [ | 1DQ2 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Canavalia_ensiformis Canavalia ensiformis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DQ2 OCA]. | ||
==Reference== | ==Reference== | ||
The structural features of concanavalin A governing non-proline peptide isomerization., Bouckaert J, Dewallef Y, Poortmans F, Wyns L, Loris R, J Biol Chem. 2000 Jun 30;275(26):19778-87. PMID:[http:// | The structural features of concanavalin A governing non-proline peptide isomerization., Bouckaert J, Dewallef Y, Poortmans F, Wyns L, Loris R, J Biol Chem. 2000 Jun 30;275(26):19778-87. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10748006 10748006] | ||
[[Category: Canavalia ensiformis]] | [[Category: Canavalia ensiformis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: Wyns, L.]] | [[Category: Wyns, L.]] | ||
[[Category: ACY]] | [[Category: ACY]] | ||
[[Category: concanavalin | [[Category: concanavalin some]] | ||
[[Category: demetallized]] | [[Category: demetallized]] | ||
[[Category: lectin]] | [[Category: lectin]] | ||
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[[Category: unlocked]] | [[Category: unlocked]] | ||
''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 10:42:29 2008'' | ||
Revision as of 11:42, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
Unlocked metal-free concanavalin A
OverviewOverview
The reversible binding of manganese and calcium to concanavalin A determines the carbohydrate binding of the lectin by inducing large conformational changes. These changes are governed by the isomerization of a non-proline peptide bond, Ala-207-Asp-208, positioned in a beta-strand in between the calcium binding site S2 and the carbohydrate specificity-determining loop. The replacement of calcium by manganese allowed us to investigate the structures of the carbohydrate binding, locked state and the inactive, unlocked state of concanavalin A, both with and without metal ions bound. Crystals of unlocked metal-free concanavalin A convert to the locked form with the binding of two Mn(2+) ions. Removal of these ions from the crystals traps metal-free concanavalin A in its locked state, a minority species in solution. The ligation of a metal ion in S2 to unlocked concanavalin A causes bending of the beta-strand foregoing the S2 ligand residues Asp-10 and Tyr-12. This bending disrupts conventional beta-sheet hydrogen bonding and forces the Thr-11 side chain against the Ala-207-Asp-208 peptide bond. The steric strain exerted by Thr-11 is presumed to drive the trans-to-cis isomerization. Upon isomerization, Asp-208 flips into its carbohydrate binding position, and the conformation of the carbohydrate specificity determining loop changes dramatically.
About this StructureAbout this Structure
1DQ2 is a Single protein structure of sequence from Canavalia ensiformis. Full crystallographic information is available from OCA.
ReferenceReference
The structural features of concanavalin A governing non-proline peptide isomerization., Bouckaert J, Dewallef Y, Poortmans F, Wyns L, Loris R, J Biol Chem. 2000 Jun 30;275(26):19778-87. PMID:10748006
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