1qdc
From Proteopedia
(New page: 200px<br /><applet load="1qdc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qdc, resolution 2.0Å" /> '''MAN(APLHA1-6)MAN(ALPH...) |
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| - | [[Image:1qdc.jpg|left|200px]]<br /><applet load="1qdc" size=" | + | [[Image:1qdc.jpg|left|200px]]<br /><applet load="1qdc" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qdc, resolution 2.0Å" /> | caption="1qdc, resolution 2.0Å" /> | ||
'''MAN(APLHA1-6)MAN(ALPHA1-O)METHYL CONCANAVALIN A COMPLEX'''<br /> | '''MAN(APLHA1-6)MAN(ALPHA1-O)METHYL CONCANAVALIN A COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structures of concanavalin A in complex with | + | The crystal structures of concanavalin A in complex with Man(alpha1-6)Man(alpha1-O)Me and Man(alpha1-3)Man(alpha1-O)Me were determined at resolutions of 2.0 and 2.8 A, respectively. In both structures, the O-1-linked mannose binds in the conserved monosaccharide-binding site. The O-3-linked mannose of Man(alpha1-3)Man(alpha1-O)Me binds in the hydrophobic subsite formed by Tyr-12, Tyr-100, and Leu-99. The shielding of a hydrophobic surface is consistent with the associated large heat capacity change. The O-6-linked mannose of Man(alpha1-6)Man(alpha1-O)Me binds in the same subsite formed by Tyr-12 and Asp-16 as the reducing mannose of the highly specific trimannose Man(alpha1-3)[Man(alpha1-6)]Man(alpha1-O)Me. However, it is much less tightly bound. Its O-2 hydroxyl makes no hydrogen bond with the conserved water 1. Water 1 is present in all the sugar-containing concanavalin A structures and increases the complementarity between the protein-binding surface and the sugar, but is not necessarily a hydrogen-bonding partner. A water analysis of the carbohydrate-binding site revealed a conserved water molecule replacing O-4 on the alpha1-3-linked arm of the trimannose. No such water is found for the reducing or O-6-linked mannose. Our data indicate that the central mannose of Man(alpha1-3)[Man(alpha1-6)]Man(alpha1-O)Me primarily functions as a hinge between the two outer subsites. |
==About this Structure== | ==About this Structure== | ||
| - | 1QDC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Canavalia_ensiformis Canavalia ensiformis] with MN, CA and CL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1QDC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Canavalia_ensiformis Canavalia ensiformis] with <scene name='pdbligand=MN:'>MN</scene>, <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=CL:'>CL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QDC OCA]. |
==Reference== | ==Reference== | ||
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[[Category: plant lectin]] | [[Category: plant lectin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:38:27 2008'' |
Revision as of 12:38, 21 February 2008
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MAN(APLHA1-6)MAN(ALPHA1-O)METHYL CONCANAVALIN A COMPLEX
Overview
The crystal structures of concanavalin A in complex with Man(alpha1-6)Man(alpha1-O)Me and Man(alpha1-3)Man(alpha1-O)Me were determined at resolutions of 2.0 and 2.8 A, respectively. In both structures, the O-1-linked mannose binds in the conserved monosaccharide-binding site. The O-3-linked mannose of Man(alpha1-3)Man(alpha1-O)Me binds in the hydrophobic subsite formed by Tyr-12, Tyr-100, and Leu-99. The shielding of a hydrophobic surface is consistent with the associated large heat capacity change. The O-6-linked mannose of Man(alpha1-6)Man(alpha1-O)Me binds in the same subsite formed by Tyr-12 and Asp-16 as the reducing mannose of the highly specific trimannose Man(alpha1-3)[Man(alpha1-6)]Man(alpha1-O)Me. However, it is much less tightly bound. Its O-2 hydroxyl makes no hydrogen bond with the conserved water 1. Water 1 is present in all the sugar-containing concanavalin A structures and increases the complementarity between the protein-binding surface and the sugar, but is not necessarily a hydrogen-bonding partner. A water analysis of the carbohydrate-binding site revealed a conserved water molecule replacing O-4 on the alpha1-3-linked arm of the trimannose. No such water is found for the reducing or O-6-linked mannose. Our data indicate that the central mannose of Man(alpha1-3)[Man(alpha1-6)]Man(alpha1-O)Me primarily functions as a hinge between the two outer subsites.
About this Structure
1QDC is a Single protein structure of sequence from Canavalia ensiformis with , and as ligands. Full crystallographic information is available from OCA.
Reference
The crystal structures of Man(alpha1-3)Man(alpha1-O)Me and Man(alpha1-6)Man(alpha1-O)Me in complex with concanavalin A., Bouckaert J, Hamelryck TW, Wyns L, Loris R, J Biol Chem. 1999 Oct 8;274(41):29188-95. PMID:10506175
Page seeded by OCA on Thu Feb 21 14:38:27 2008
Categories: Canavalia ensiformis | Single protein | Bouckaert, J. | Loris, R. | Wyns, L. | CA | CL | MN | Carbohydrate binding | Concanavalin a | Dimannose | Plant lectin
