1dq6
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1dq6.jpg|left|200px]] | [[Image:1dq6.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1dq6", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | + | --> | |
| - | + | {{STRUCTURE_1dq6| PDB=1dq6 | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''Manganese;Manganese concanavalin A at pH 7.0''' | '''Manganese;Manganese concanavalin A at pH 7.0''' | ||
| Line 30: | Line 27: | ||
[[Category: Poortmans, F.]] | [[Category: Poortmans, F.]] | ||
[[Category: Wyns, L.]] | [[Category: Wyns, L.]] | ||
| - | [[Category: | + | [[Category: Binuclear]] |
| - | [[Category: | + | [[Category: Concanavalin some]] |
| - | [[Category: | + | [[Category: Lectin]] |
| - | [[Category: | + | [[Category: Manganese]] |
| - | [[Category: | + | [[Category: Metal binding]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 14:08:39 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 11:08, 2 May 2008
Manganese;Manganese concanavalin A at pH 7.0
Overview
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 Structure
1DQ6 is a Single protein structure of sequence from Canavalia ensiformis. Full crystallographic information is available from OCA.
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:10748006 Page seeded by OCA on Fri May 2 14:08:39 2008
