1QDC

MAN(APLHA1-6)MAN(ALPHA1-O)METHYL CONCANAVALIN A COMPLEX

1QDC の概要

• エントリーDOI: 10.2210/pdb1qdc/pdb
• 分子名称: PROTEIN (CONCANAVALIN A), alpha-D-mannopyranose-(1-6)-methyl alpha-D-mannopyranoside, MANGANESE (II) ION, ... (6 entities in total)
• 機能のキーワード: plant lectin, carbohydrate binding, dimannose, concanavalin a, sugar binding protein
• 由来する生物種: Canavalia ensiformis (jack bean)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 104330.35

構造登録者

Bouckaert, J.,Loris, R.,Wyns, L. (登録日: 1998-07-14, 公開日: 1999-10-14, 最終更新日: 2023-08-16)

主引用文献

Bouckaert, J.,Hamelryck, T.W.,Wyns, L.,Loris, R.
The crystal structures of Man(alpha1-3)Man(alpha1-O)Me and Man(alpha1-6)Man(alpha1-O)Me in complex with concanavalin A.
J.Biol.Chem., 274:29188-29195, 1999

PubMed Abstract: 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.

PubMed: 10506175
DOI: 10.1074/jbc.274.41.29188

実験手法

X-RAY DIFFRACTION (2 Å)