1R14

Carbohydrate recognition and neck domains of surfactant protein A (Sp-A) containing samarium

1R14 の概要

• エントリーDOI: 10.2210/pdb1r14/pdb
• 関連するPDBエントリー: 1R13
• 分子名称: Pulmonary surfactant-associated protein A, SAMARIUM (III) ION, 2-(N-MORPHOLINO)-ETHANESULFONIC ACID, ... (4 entities in total)
• 機能のキーワード: crd, alpha helical neck region, sugar binding protein
• 由来する生物種: Rattus norvegicus (Norway rat)
• 細胞内の位置: Secreted, extracellular space, extracellular matrix: P08427
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17168.54

構造登録者

Head, J.F.,Mealy, T.R.,McCormack, F.X.,Seaton, B.A. (登録日: 2003-09-23, 公開日: 2003-11-11, 最終更新日: 2024-10-09)

主引用文献

Head, J.F.,Mealy, T.R.,McCormack, F.X.,Seaton, B.A.
Crystal structure of trimeric carbohydrate recognition and neck domains of surfactant protein A
J.Biol.Chem., 278:43254-43260, 2003

PubMed Abstract: Surfactant protein A (SP-A), one of four proteins associated with pulmonary surfactant, binds with high affinity to alveolar phospholipid membranes, positioning the protein at the first line of defense against inhaled pathogens. SP-A exhibits both calcium-dependent carbohydrate binding, a characteristic of the collectin family, and specific interactions with lipid membrane components. The crystal structure of the trimeric carbohydrate recognition domain and neck domain of SP-A was solved to 2.1-A resolution with multiwavelength anomalous dispersion phasing from samarium. Two metal binding sites were identified, one in the highly conserved lectin site and the other 8.5 A away. The interdomain carbohydrate recognition domain-neck angle is significantly less in SP-A than in the homologous collectins, surfactant protein D, and mannose-binding protein. This conformational difference may endow the SP-A trimer with a more extensive hydrophobic surface capable of binding lipophilic membrane components. The appearance of this surface suggests a putative binding region for membrane-derived SP-A ligands such as phosphatidylcholine and lipid A, the endotoxic lipid component of bacterial lipopolysaccharide that mediates the potentially lethal effects of Gram-negative bacterial infection.

PubMed: 12913002
DOI: 10.1074/jbc.M305628200

実験手法

X-RAY DIFFRACTION (2.5 Å)