1JN2

Crystal Structure of meso-tetrasulphonatophenyl porphyrin complexed with Concanavalin A

1JN2 の概要

• エントリーDOI: 10.2210/pdb1jn2/pdb
• 分子名称: Concanavalin-A, CALCIUM ION, MANGANESE (II) ION, ... (5 entities in total)
• 機能のキーワード: lectin, sugar binding protein
• 由来する生物種: Canavalia ensiformis (Jack bean); 詳細
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26656.42

構造登録者

Goel, M.,Jain, D.,Kaur, K.J.,Kenoth, R.,Maiya, B.G.,Swamy, M.J.,Salunke, D.M. (登録日: 2001-07-22, 公開日: 2003-07-01, 最終更新日: 2024-02-07)

主引用文献

Goel, M.,Jain, D.,Kaur, K.J.,Kenoth, R.,Maiya, B.G.,Swamy, M.J.,Salunke, D.M.
Functional equality in the absence of structural similarity: an added dimension to molecular mimicry
J.Biol.Chem., 276:39277-39281, 2000

PubMed Abstract: The crystal structure of meso-tetrasulfonatophenylporphyrin complexed with concanavalin A (ConA) was determined at 1.9 A resolution. Comparison of this structure with that of ConA bound to methyl alpha-d-mannopyranoside provided direct structural evidence of molecular mimicry in the context of ligand receptor binding. The sulfonatophenyl group of meso-tetrasulfonatophenylporphyrin occupies the same binding site on ConA as that of methyl alpha-d-mannopyranoside, a natural ligand. A pair of stacked porphyrin molecules stabilizes the crystal structure by end-to-end cross-linking with ConA resulting in a network similar to that observed upon agglutination of cells by lectins. The porphyrin binds to ConA predominantly through hydrogen bonds and water-mediated interactions. The sandwiched water molecules in the complex play a cementing role, facilitating favorable binding of porphyrin. Seven of the eight hydrogen bonds observed between methyl alpha-d-mannopyranoside and ConA are mimicked by the sulfonatophenyl group of porphyrin after incorporating two water molecules. Thus, the similarity in chemical interactions was manifested in terms of functional mimicry despite the obvious structural dissimilarity between the sugar and the porphyrin.

PubMed: 11504727
DOI: 10.1074/jbc.M105387200

実験手法

X-RAY DIFFRACTION (1.9 Å)