1exr
From Proteopedia
(New page: 200px<br /><applet load="1exr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1exr, resolution 1.00Å" /> '''THE 1.0 ANGSTROM CRY...) |
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| - | [[Image:1exr.jpg|left|200px]]<br /><applet load="1exr" size=" | + | [[Image:1exr.jpg|left|200px]]<br /><applet load="1exr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1exr, resolution 1.00Å" /> | caption="1exr, resolution 1.00Å" /> | ||
'''THE 1.0 ANGSTROM CRYSTAL STRUCTURE OF CA+2 BOUND CALMODULIN'''<br /> | '''THE 1.0 ANGSTROM CRYSTAL STRUCTURE OF CA+2 BOUND CALMODULIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Calmodulin (CaM) is a highly conserved 17 kDa eukaryotic protein that can | + | Calmodulin (CaM) is a highly conserved 17 kDa eukaryotic protein that can bind specifically to over 100 protein targets in response to a Ca(2+) signal. Ca(2+)-CaM requires a considerable degree of structural plasticity to accomplish this physiological role; however, the nature and extent of this plasticity remain poorly characterized. Here, we present the 1.0 A crystal structure of Paramecium tetraurelia Ca(2+)-CaM, including 36 discretely disordered residues and a fifth Ca(2+) that mediates a crystal contact. The 36 discretely disordered residues are located primarily in the central helix and the two hydrophobic binding pockets, and reveal correlated side-chain disorder that may assist target-specific deformation of the binding pockets. Evidence of domain displacements and discrete backbone disorder is provided by translation-libration-screw (TLS) analysis and multiconformer models of protein disorder, respectively. In total, the evidence for disorder at every accessible length-scale in Ca(2+)-CaM suggests that the protein occupies a large number of hierarchically arranged conformational substates in the crystalline environment and may sample a quasi-continuous spectrum of conformations in solution. Therefore, we propose that the functionally distinct forms of CaM are less structurally distinct than previously believed, and that the different activities of CaM in response to Ca(2+) may result primarily from Ca(2+)-mediated alterations in the dynamics of the protein. |
==About this Structure== | ==About this Structure== | ||
| - | 1EXR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Paramecium_tetraurelia Paramecium tetraurelia] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1EXR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Paramecium_tetraurelia Paramecium tetraurelia] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EXR OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Paramecium tetraurelia]] | [[Category: Paramecium tetraurelia]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Brunger, A | + | [[Category: Brunger, A T.]] |
| - | [[Category: Wilson, M | + | [[Category: Wilson, M A.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: calmodulin]] | [[Category: calmodulin]] | ||
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[[Category: high resolution]] | [[Category: high resolution]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:32:39 2008'' |
Revision as of 10:32, 21 February 2008
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THE 1.0 ANGSTROM CRYSTAL STRUCTURE OF CA+2 BOUND CALMODULIN
Overview
Calmodulin (CaM) is a highly conserved 17 kDa eukaryotic protein that can bind specifically to over 100 protein targets in response to a Ca(2+) signal. Ca(2+)-CaM requires a considerable degree of structural plasticity to accomplish this physiological role; however, the nature and extent of this plasticity remain poorly characterized. Here, we present the 1.0 A crystal structure of Paramecium tetraurelia Ca(2+)-CaM, including 36 discretely disordered residues and a fifth Ca(2+) that mediates a crystal contact. The 36 discretely disordered residues are located primarily in the central helix and the two hydrophobic binding pockets, and reveal correlated side-chain disorder that may assist target-specific deformation of the binding pockets. Evidence of domain displacements and discrete backbone disorder is provided by translation-libration-screw (TLS) analysis and multiconformer models of protein disorder, respectively. In total, the evidence for disorder at every accessible length-scale in Ca(2+)-CaM suggests that the protein occupies a large number of hierarchically arranged conformational substates in the crystalline environment and may sample a quasi-continuous spectrum of conformations in solution. Therefore, we propose that the functionally distinct forms of CaM are less structurally distinct than previously believed, and that the different activities of CaM in response to Ca(2+) may result primarily from Ca(2+)-mediated alterations in the dynamics of the protein.
About this Structure
1EXR is a Single protein structure of sequence from Paramecium tetraurelia with as ligand. Full crystallographic information is available from OCA.
Reference
The 1.0 A crystal structure of Ca(2+)-bound calmodulin: an analysis of disorder and implications for functionally relevant plasticity., Wilson MA, Brunger AT, J Mol Biol. 2000 Sep 1;301(5):1237-56. PMID:10966818
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