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1gzx
From Proteopedia
| 1gzx, resolution 2.10Å () | |||||||||
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| Sites: | |||||||||
| Ligands: | , | ||||||||
| Domains: | globin | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
OXY T STATE HAEMOGLOBIN: OXYGEN BOUND AT ALL FOUR HAEMS
The cooperative binding of oxygen by haemoglobin results from restraints on ligand binding in the T state. The unfavourable interactions made by the ligands at the haems destabilise the T state and favour the high affinity R state. The T <==> R equilibrium leads, in the presence of a ligand, to a rapid increase in the R state population and therefore generates cooperative binding. There is now considerable understanding of this phenomenon, but the interactions that reduce ligand affinity in the T state have not yet been fully explored, owing to the difficulties in preparing T state haemoglobin crystals in which all the subunits are oxygenated. A protocol has been developed to oxygenate deoxy T state adult human haemoglobin (HbA) crystals in air at 4 C at all four haems without significant loss of crystalline order. The X-ray crystal structure, determined to 2.1 A spacing, shows significant changes in the alpha and beta haem pockets as well as changes at the alpha(1)beta(2) interface in the direction of the R quaternary structure. Most of the shifts and deviations from deoxy T state HbA are similar to, but larger than, those previously observed in the T state met and other partially liganded T state forms. They provide clear evidence of haem-haem interaction in the T state.
Crystal structure of T state haemoglobin with oxygen bound at all four haems., Paoli M, Liddington R, Tame J, Wilkinson A, Dodson G, J Mol Biol. 1996 Mar 8;256(4):775-92. PMID:8642597
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1GZX is a 4 chains structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
- Paoli M, Liddington R, Tame J, Wilkinson A, Dodson G. Crystal structure of T state haemoglobin with oxygen bound at all four haems. J Mol Biol. 1996 Mar 8;256(4):775-92. PMID:8642597 doi:10.1006/jmbi.1996.0124
Page seeded by OCA on Tue Feb 17 12:17:05 2009
