1qjs
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The ubiquitous use of heme in animals poses severe biological and chemical | + | The ubiquitous use of heme in animals poses severe biological and chemical challenges. Free heme is toxic to cells and is a potential source of iron for pathogens. For protection, especially in conditions of trauma, inflammation and hemolysis, and to maintain iron homeostasis, a high-affinity binding protein, hemopexin, is required. Hemopexin binds heme with the highest affinity of any known protein, but releases it into cells via specific receptors. The crystal structure of the heme-hemopexin complex reveals a novel heme binding site, formed between two similar four-bladed beta-propeller domains and bounded by the interdomain linker. The ligand is bound to two histidine residues in a pocket dominated by aromatic and basic groups. Further stabilization is achieved by the association of the two beta-propeller domains, which form an extensive polar interface that includes a cushion of ordered water molecules. We propose mechanisms by which these structural features provide the dual function of heme binding and release. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Oryctolagus cuniculus]] | [[Category: Oryctolagus cuniculus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Baker, E | + | [[Category: Baker, E N.]] |
| - | [[Category: Baker, H | + | [[Category: Baker, H M.]] |
| - | [[Category: Morgan, W | + | [[Category: Morgan, W T.]] |
[[Category: Paoli, M.]] | [[Category: Paoli, M.]] | ||
[[Category: Smith, A.]] | [[Category: Smith, A.]] | ||
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[[Category: iron metabolism]] | [[Category: iron metabolism]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:40:24 2008'' |
Revision as of 12:40, 21 February 2008
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MAMMALIAN BLOOD SERUM HAEMOPEXIN GLYCOSYLATED-NATIVE PROTEIN AND IN COMPLEX WITH ITS LIGAND HAEM
Overview
The ubiquitous use of heme in animals poses severe biological and chemical challenges. Free heme is toxic to cells and is a potential source of iron for pathogens. For protection, especially in conditions of trauma, inflammation and hemolysis, and to maintain iron homeostasis, a high-affinity binding protein, hemopexin, is required. Hemopexin binds heme with the highest affinity of any known protein, but releases it into cells via specific receptors. The crystal structure of the heme-hemopexin complex reveals a novel heme binding site, formed between two similar four-bladed beta-propeller domains and bounded by the interdomain linker. The ligand is bound to two histidine residues in a pocket dominated by aromatic and basic groups. Further stabilization is achieved by the association of the two beta-propeller domains, which form an extensive polar interface that includes a cushion of ordered water molecules. We propose mechanisms by which these structural features provide the dual function of heme binding and release.
About this Structure
1QJS is a Single protein structure of sequence from Oryctolagus cuniculus with , , and as ligands. Known structural/functional Sites: and . Full crystallographic information is available from OCA.
Reference
Crystal structure of hemopexin reveals a novel high-affinity heme site formed between two beta-propeller domains., Paoli M, Anderson BF, Baker HM, Morgan WT, Smith A, Baker EN, Nat Struct Biol. 1999 Oct;6(10):926-31. PMID:10504726
Page seeded by OCA on Thu Feb 21 14:40:24 2008
Categories: Oryctolagus cuniculus | Single protein | Baker, E N. | Baker, H M. | Morgan, W T. | Paoli, M. | Smith, A. | CL | HEM | NA | PO4 | Beta propeller | Haem binding and transport | Iron metabolism
