1fsx
From Proteopedia
(New page: 200px<br /> <applet load="1fsx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1fsx, resolution 2.1Å" /> '''THE X-RAY STRUCTURE ...) |
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| - | [[Image:1fsx.gif|left|200px]]<br /> | + | [[Image:1fsx.gif|left|200px]]<br /><applet load="1fsx" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1fsx" size=" | + | |
caption="1fsx, resolution 2.1Å" /> | caption="1fsx, resolution 2.1Å" /> | ||
'''THE X-RAY STRUCTURE DETERMINATION OF BOVINE CARBONMONOXY HB AT 2.1 A RESOLUTION AND ITS RELATIONSHIP TO THE QUATERNARY STRUCTURE OF OTHER HB CRYSTAL FORMS'''<br /> | '''THE X-RAY STRUCTURE DETERMINATION OF BOVINE CARBONMONOXY HB AT 2.1 A RESOLUTION AND ITS RELATIONSHIP TO THE QUATERNARY STRUCTURE OF OTHER HB CRYSTAL FORMS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Crystallographic studies of the intermediate states between unliganded and | + | Crystallographic studies of the intermediate states between unliganded and fully liganded hemoglobin (Hb) have revealed a large range of subtle but functionally important structural differences. Only one T state has been reported, whereas three other quaternary states (the R state, B state, and R2 or Y state) for liganded Hb have been characterized; other studies have defined liganded Hbs that are intermediate between the T and R states. The high-salt crystal structure of bovine carbonmonoxy (CO bovine) Hb has been determined at a resolution of 2.1 A and is described here. A detailed comparison with other crystallographically solved Hb forms (T, R, R2 or Y) shows that the quaternary structure of CO bovine Hb closely resembles R state Hb. However, our analysis of these structures has identified several important differences between CO bovine Hb and R state Hb. Compared with the R state structures, the beta-subunit N-terminal region has shifted closer to the central water cavity in CO bovine Hb. In addition, both the alpha- and beta-subunits in CO bovine Hb have more constrained heme environments that appear to be intermediate between the T and R states. Moreover, the distal pocket of the beta-subunit heme in CO bovine Hb shows significantly closer interaction between the bound CO ligand and the Hb distal residues Val 63(E11) and His 63(E7). The constrained heme groups and the increased steric contact involving the CO ligand and the distal heme residues relative to human Hb may explain in part the low intrinsic oxygen affinity of bovine Hb. |
==About this Structure== | ==About this Structure== | ||
| - | 1FSX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CMO and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1FSX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CMO:'>CMO</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FSX OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Abraham, D | + | [[Category: Abraham, D J.]] |
| - | [[Category: Safo, M | + | [[Category: Safo, M K.]] |
[[Category: CMO]] | [[Category: CMO]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
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[[Category: r-state]] | [[Category: r-state]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:42:16 2008'' |
Revision as of 10:42, 21 February 2008
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THE X-RAY STRUCTURE DETERMINATION OF BOVINE CARBONMONOXY HB AT 2.1 A RESOLUTION AND ITS RELATIONSHIP TO THE QUATERNARY STRUCTURE OF OTHER HB CRYSTAL FORMS
Overview
Crystallographic studies of the intermediate states between unliganded and fully liganded hemoglobin (Hb) have revealed a large range of subtle but functionally important structural differences. Only one T state has been reported, whereas three other quaternary states (the R state, B state, and R2 or Y state) for liganded Hb have been characterized; other studies have defined liganded Hbs that are intermediate between the T and R states. The high-salt crystal structure of bovine carbonmonoxy (CO bovine) Hb has been determined at a resolution of 2.1 A and is described here. A detailed comparison with other crystallographically solved Hb forms (T, R, R2 or Y) shows that the quaternary structure of CO bovine Hb closely resembles R state Hb. However, our analysis of these structures has identified several important differences between CO bovine Hb and R state Hb. Compared with the R state structures, the beta-subunit N-terminal region has shifted closer to the central water cavity in CO bovine Hb. In addition, both the alpha- and beta-subunits in CO bovine Hb have more constrained heme environments that appear to be intermediate between the T and R states. Moreover, the distal pocket of the beta-subunit heme in CO bovine Hb shows significantly closer interaction between the bound CO ligand and the Hb distal residues Val 63(E11) and His 63(E7). The constrained heme groups and the increased steric contact involving the CO ligand and the distal heme residues relative to human Hb may explain in part the low intrinsic oxygen affinity of bovine Hb.
About this Structure
1FSX is a Protein complex structure of sequences from Bos taurus with and as ligands. Full crystallographic information is available from OCA.
Reference
The X-ray structure determination of bovine carbonmonoxy hemoglobin at 2.1 A resoultion and its relationship to the quaternary structures of other hemoglobin crystal froms., Safo MK, Abraham DJ, Protein Sci. 2001 Jun;10(6):1091-9. PMID:11369847
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