2oif
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The evolution of oxygen transport hemoglobins occurred on at least two | + | The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport "leghemoglobins" evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Hordeum vulgare]] | [[Category: Hordeum vulgare]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Hoy, J | + | [[Category: Hoy, J A.]] |
[[Category: CYN]] | [[Category: CYN]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
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[[Category: symbiotic]] | [[Category: symbiotic]] | ||
| - | ''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 18:18:53 2008'' |
Revision as of 16:18, 21 February 2008
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The crystal structure of ferric cyanide bound barley hexacoordinate hemoglobin.
Overview
The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport "leghemoglobins" evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins.
About this Structure
2OIF is a Single protein structure of sequence from Hordeum vulgare with , and as ligands. Full crystallographic information is available from OCA.
Reference
Plant hemoglobins: a molecular fossil record for the evolution of oxygen transport., Hoy JA, Robinson H, Trent JT 3rd, Kakar S, Smagghe BJ, Hargrove MS, J Mol Biol. 2007 Aug 3;371(1):168-79. Epub 2007 May 18. PMID:17560601
Page seeded by OCA on Thu Feb 21 18:18:53 2008
