1R14
Carbohydrate recognition and neck domains of surfactant protein A (Sp-A) containing samarium
Summary for 1R14
| Entry DOI | 10.2210/pdb1r14/pdb |
| Related | 1R13 |
| Descriptor | Pulmonary surfactant-associated protein A, SAMARIUM (III) ION, 2-(N-MORPHOLINO)-ETHANESULFONIC ACID, ... (4 entities in total) |
| Functional Keywords | crd, alpha helical neck region, sugar binding protein |
| Biological source | Rattus norvegicus (Norway rat) |
| Cellular location | Secreted, extracellular space, extracellular matrix: P08427 |
| Total number of polymer chains | 1 |
| Total formula weight | 17168.54 |
| Authors | Head, J.F.,Mealy, T.R.,McCormack, F.X.,Seaton, B.A. (deposition date: 2003-09-23, release date: 2003-11-11, Last modification date: 2024-10-09) |
| Primary citation | 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 Cited by 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: 12913002DOI: 10.1074/jbc.M305628200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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