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1b8l
From Proteopedia
(New page: 200px<br /><applet load="1b8l" size="450" color="white" frame="true" align="right" spinBox="true" caption="1b8l, resolution 1.70Å" /> '''Calcium-bound D51A/E...) |
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| - | [[Image:1b8l.gif|left|200px]]<br /><applet load="1b8l" size=" | + | [[Image:1b8l.gif|left|200px]]<br /><applet load="1b8l" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1b8l, resolution 1.70Å" /> | caption="1b8l, resolution 1.70Å" /> | ||
'''Calcium-bound D51A/E101D/F102W Triple Mutant of Beta Carp Parvalbumin'''<br /> | '''Calcium-bound D51A/E101D/F102W Triple Mutant of Beta Carp Parvalbumin'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: The EF-hand family is a large set of Ca(2+)-binding proteins | + | BACKGROUND: The EF-hand family is a large set of Ca(2+)-binding proteins that contain characteristic helix-loop-helix binding motifs that are highly conserved in sequence. Members of this family include parvalbumin and many prominent regulatory proteins such as calmodulin and troponin C. EF-hand proteins are involved in a variety of physiological processes including cell-cycle regulation, second messenger production, muscle contraction, microtubule organization and vision. RESULTS: We have determined the structures of parvalbumin mutants designed to explore the role of the last coordinating residue of the Ca(2+)-binding loop. An E101D substitution has been made in the parvalbumin EF site. The substitution decreases the Ca(2+)-binding affinity 100-fold and increases the Mg(2+)-binding affinity 10-fold. Both the Ca(2+)- and Mg(2+)-bound structures have been determined, and a structural basis has been proposed for the metal-ion-binding properties. CONCLUSIONS: The E101D mutation does not affect the Mg(2+) coordination geometry of the binding loop, but it does pull the F helix 1.1 A towards the loop. The E101D-Ca(2+) structure reveals that this mutant cannot obtain the sevenfold coordination preferred by Ca(2+), presumably because of strain limits imposed by tertiary structure. Analysis of these results relative to previously reported structural information supports a model wherein the characteristics of the last coordinating residue and the plasticity of the Ca(2+)-binding loop delimit the allowable geometries for the coordinating sphere. |
==About this Structure== | ==About this Structure== | ||
| - | 1B8L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cyprinus_carpio Cyprinus carpio] with CO3 and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1B8L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cyprinus_carpio Cyprinus carpio] with <scene name='pdbligand=CO3:'>CO3</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B8L OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Cyprinus carpio]] | [[Category: Cyprinus carpio]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Berry, M | + | [[Category: Berry, M B.]] |
| - | [[Category: Cates, M | + | [[Category: Cates, M S.]] |
[[Category: Ho, E.]] | [[Category: Ho, E.]] | ||
| - | [[Category: Jr., G | + | [[Category: Jr., G N.Phillips.]] |
[[Category: Li, Q.]] | [[Category: Li, Q.]] | ||
| - | [[Category: Potter, J | + | [[Category: Potter, J D.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: CO3]] | [[Category: CO3]] | ||
| Line 26: | Line 26: | ||
[[Category: parvalbumin]] | [[Category: parvalbumin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:52:38 2008'' |
Revision as of 09:52, 21 February 2008
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Calcium-bound D51A/E101D/F102W Triple Mutant of Beta Carp Parvalbumin
Overview
BACKGROUND: The EF-hand family is a large set of Ca(2+)-binding proteins that contain characteristic helix-loop-helix binding motifs that are highly conserved in sequence. Members of this family include parvalbumin and many prominent regulatory proteins such as calmodulin and troponin C. EF-hand proteins are involved in a variety of physiological processes including cell-cycle regulation, second messenger production, muscle contraction, microtubule organization and vision. RESULTS: We have determined the structures of parvalbumin mutants designed to explore the role of the last coordinating residue of the Ca(2+)-binding loop. An E101D substitution has been made in the parvalbumin EF site. The substitution decreases the Ca(2+)-binding affinity 100-fold and increases the Mg(2+)-binding affinity 10-fold. Both the Ca(2+)- and Mg(2+)-bound structures have been determined, and a structural basis has been proposed for the metal-ion-binding properties. CONCLUSIONS: The E101D mutation does not affect the Mg(2+) coordination geometry of the binding loop, but it does pull the F helix 1.1 A towards the loop. The E101D-Ca(2+) structure reveals that this mutant cannot obtain the sevenfold coordination preferred by Ca(2+), presumably because of strain limits imposed by tertiary structure. Analysis of these results relative to previously reported structural information supports a model wherein the characteristics of the last coordinating residue and the plasticity of the Ca(2+)-binding loop delimit the allowable geometries for the coordinating sphere.
About this Structure
1B8L is a Single protein structure of sequence from Cyprinus carpio with and as ligands. Full crystallographic information is available from OCA.
Reference
Metal-ion affinity and specificity in EF-hand proteins: coordination geometry and domain plasticity in parvalbumin., Cates MS, Berry MB, Ho EL, Li Q, Potter JD, Phillips GN Jr, Structure. 1999 Oct 15;7(10):1269-78. PMID:10545326
Page seeded by OCA on Thu Feb 21 11:52:38 2008
