1j40: Difference between revisions
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[[Image:1j40.gif|left|200px]]<br /> | [[Image:1j40.gif|left|200px]]<br /><applet load="1j40" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1j40" size=" | |||
caption="1j40, resolution 1.45Å" /> | caption="1j40, resolution 1.45Å" /> | ||
'''Direct observation of photolysis-induced tertiary structural changes in human haemoglobin; Crystal structure of alpha(Ni)-beta(Fe-CO) hemoglobin (laser unphotolysed)'''<br /> | '''Direct observation of photolysis-induced tertiary structural changes in human haemoglobin; Crystal structure of alpha(Ni)-beta(Fe-CO) hemoglobin (laser unphotolysed)'''<br /> | ||
==Overview== | ==Overview== | ||
Human Hb, an alpha2beta2 tetrameric oxygen transport protein that switches | Human Hb, an alpha2beta2 tetrameric oxygen transport protein that switches from a T (tense) to an R (relaxed) quaternary structure during oxygenation, has long served as a model for studying protein allostery in general. Time-resolved spectroscopic measurements after photodissociation of CO-liganded Hb have played a central role in exploring both protein dynamical responses and molecular cooperativity, but the direct visualization and the structural consequences of photodeligation have not yet been reported. Here we present an x-ray study of structural changes induced by photodissociation of half-liganded T-state and fully liganded R-state human Hb at cryogenic temperatures (25-35 K). On photodissociation of CO, structural changes involving the heme and the F-helix are more marked in the alpha subunit than in the beta subunit, and more subtle in the R state than in the T state. Photodeligation causes a significant sliding motion of the T-state beta heme. Our results establish that the structural basis of the low affinity of the T state is radically different between the subunits, because of differences in the packing and chemical tension at the hemes. | ||
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
1J40 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 HNI, HEM, CMO and 2FU as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1J40 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=HNI:'>HNI</scene>, <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=CMO:'>CMO</scene> and <scene name='pdbligand=2FU:'>2FU</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1J40 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Adachi, S.]] | [[Category: Adachi, S.]] | ||
[[Category: Park, S | [[Category: Park, S Y.]] | ||
[[Category: RSGI, RIKEN | [[Category: RSGI, RIKEN Structural Genomics/Proteomics Initiative.]] | ||
[[Category: Shibayama, N.]] | [[Category: Shibayama, N.]] | ||
[[Category: Shiro, Y.]] | [[Category: Shiro, Y.]] | ||
[[Category: Tame, J | [[Category: Tame, J R.H.]] | ||
[[Category: 2FU]] | [[Category: 2FU]] | ||
[[Category: CMO]] | [[Category: CMO]] | ||
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[[Category: tertiary structure changes]] | [[Category: tertiary structure changes]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:18:42 2008'' | ||