2grh
From Proteopedia
(New page: 200px<br /> <applet load="2grh" size="450" color="white" frame="true" align="right" spinBox="true" caption="2grh, resolution 1.50Å" /> '''M37V mutant of Scap...) |
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| - | [[Image:2grh.gif|left|200px]]<br /> | + | [[Image:2grh.gif|left|200px]]<br /><applet load="2grh" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="2grh" size=" | + | |
caption="2grh, resolution 1.50Å" /> | caption="2grh, resolution 1.50Å" /> | ||
'''M37V mutant of Scapharca dimeric hemoglobin, with CO bound'''<br /> | '''M37V mutant of Scapharca dimeric hemoglobin, with CO bound'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Protein allostery provides mechanisms for regulation of biological | + | Protein allostery provides mechanisms for regulation of biological function at the molecular level. We present here an investigation of global, ligand-induced allosteric transition in a protein by time-resolved x-ray diffraction. The study provides a view of structural changes in single crystals of Scapharca dimeric hemoglobin as they proceed in real time, from 5 ns to 80 micros after ligand photodissociation. A tertiary intermediate structure forms rapidly (<5 ns) as the protein responds to the presence of an unliganded heme within each R-state protein subunit, with key structural changes observed in the heme groups, neighboring residues, and interface water molecules. This intermediate lays a foundation for the concerted tertiary and quaternary structural changes that occur on a microsecond time scale and are associated with the transition to a low-affinity T-state structure. Reversal of these changes shows a considerable lag as a T-like structure persists well after ligand rebinding, suggesting a slow T-to-R transition. |
==About this Structure== | ==About this Structure== | ||
| - | 2GRH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Scapharca_inaequivalvis Scapharca inaequivalvis] with HEM and CMO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2GRH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Scapharca_inaequivalvis Scapharca inaequivalvis] with <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=CMO:'>CMO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GRH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Scapharca inaequivalvis]] | [[Category: Scapharca inaequivalvis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Jr., W | + | [[Category: Jr., W E.Royer.]] |
| - | [[Category: Knapp, J | + | [[Category: Knapp, J E.]] |
[[Category: Pahl, R.]] | [[Category: Pahl, R.]] | ||
[[Category: Srajer, V.]] | [[Category: Srajer, V.]] | ||
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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 17:34:32 2008'' |
Revision as of 15:34, 21 February 2008
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M37V mutant of Scapharca dimeric hemoglobin, with CO bound
Overview
Protein allostery provides mechanisms for regulation of biological function at the molecular level. We present here an investigation of global, ligand-induced allosteric transition in a protein by time-resolved x-ray diffraction. The study provides a view of structural changes in single crystals of Scapharca dimeric hemoglobin as they proceed in real time, from 5 ns to 80 micros after ligand photodissociation. A tertiary intermediate structure forms rapidly (<5 ns) as the protein responds to the presence of an unliganded heme within each R-state protein subunit, with key structural changes observed in the heme groups, neighboring residues, and interface water molecules. This intermediate lays a foundation for the concerted tertiary and quaternary structural changes that occur on a microsecond time scale and are associated with the transition to a low-affinity T-state structure. Reversal of these changes shows a considerable lag as a T-like structure persists well after ligand rebinding, suggesting a slow T-to-R transition.
About this Structure
2GRH is a Single protein structure of sequence from Scapharca inaequivalvis with and as ligands. Full crystallographic information is available from OCA.
Reference
Allosteric action in real time: time-resolved crystallographic studies of a cooperative dimeric hemoglobin., Knapp JE, Pahl R, Srajer V, Royer WE Jr, Proc Natl Acad Sci U S A. 2006 May 16;103(20):7649-54. Epub 2006 May 9. PMID:16684887
Page seeded by OCA on Thu Feb 21 17:34:32 2008
