1coh
From Proteopedia
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| - | [[Image:1coh.gif|left|200px]]<br /> | + | [[Image:1coh.gif|left|200px]]<br /><applet load="1coh" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1coh" size=" | + | |
caption="1coh, resolution 2.9Å" /> | caption="1coh, resolution 2.9Å" /> | ||
'''STRUCTURE OF HAEMOGLOBIN IN THE DEOXY QUATERNARY STATE WITH LIGAND BOUND AT THE ALPHA HAEMS'''<br /> | '''STRUCTURE OF HAEMOGLOBIN IN THE DEOXY QUATERNARY STATE WITH LIGAND BOUND AT THE ALPHA HAEMS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | We report the X-ray crystal structure of two analogues of human | + | We report the X-ray crystal structure of two analogues of human haemoglobin in the deoxy quaternary (T) state with ligand bound exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II) beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is analysed. In both the native deoxy and liganded T molecules, the mean plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically restrict haem tilting in the T state. We propose that strain energy develops at the contact between the haem and these residues in the liganded T-state haemoglobin, and that the strain is, in part, responsible for the low affinity of the T-state alpha haem. |
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1COH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with HEM, CMO and COH as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1COH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=CMO:'>CMO</scene> and <scene name='pdbligand=COH:'>COH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1COH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: oxygen transport]] | [[Category: oxygen transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:08:04 2008'' |
Revision as of 10:08, 21 February 2008
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STRUCTURE OF HAEMOGLOBIN IN THE DEOXY QUATERNARY STATE WITH LIGAND BOUND AT THE ALPHA HAEMS
Contents |
Overview
We report the X-ray crystal structure of two analogues of human haemoglobin in the deoxy quaternary (T) state with ligand bound exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II) beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is analysed. In both the native deoxy and liganded T molecules, the mean plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically restrict haem tilting in the T state. We propose that strain energy develops at the contact between the haem and these residues in the liganded T-state haemoglobin, and that the strain is, in part, responsible for the low affinity of the T-state alpha haem.
Disease
Known diseases associated with this structure: Erythremias, alpha- OMIM:[141800], Erythremias, beta- OMIM:[141900], Erythrocytosis OMIM:[141850], HPFH, deletion type OMIM:[141900], Heinz body anemia OMIM:[141850], Heinz body anemias, alpha- OMIM:[141800], Heinz body anemias, beta- OMIM:[141900], Hemoglobin H disease OMIM:[141850], Hypochromic microcytic anemia OMIM:[141850], Methemoglobinemias, alpha- OMIM:[141800], Methemoglobinemias, beta- OMIM:[141900], Sickle cell anemia OMIM:[141900], Thalassemia, alpha- OMIM:[141850], Thalassemia-beta, dominant inclusion-body OMIM:[141900], Thalassemias, alpha- OMIM:[141800], Thalassemias, beta- OMIM:[141900]
About this Structure
1COH is a Protein complex structure of sequences from Homo sapiens with , and as ligands. Full crystallographic information is available from OCA.
Reference
Structure of haemoglobin in the deoxy quaternary state with ligand bound at the alpha haems., Luisi B, Shibayama N, J Mol Biol. 1989 Apr 20;206(4):723-36. PMID:2738915
Page seeded by OCA on Thu Feb 21 12:08:04 2008
Categories: Homo sapiens | Protein complex | Luisi, B. | CMO | COH | HEM | Oxygen transport
