2sas
From Proteopedia
(New page: 200px<br /><applet load="2sas" size="450" color="white" frame="true" align="right" spinBox="true" caption="2sas, resolution 2.4Å" /> '''STRUCTURE OF A SARCOP...) |
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| - | [[Image:2sas.jpg|left|200px]]<br /><applet load="2sas" size=" | + | [[Image:2sas.jpg|left|200px]]<br /><applet load="2sas" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2sas, resolution 2.4Å" /> | caption="2sas, resolution 2.4Å" /> | ||
'''STRUCTURE OF A SARCOPLASMIC CALCIUM-BINDING PROTEIN FROM AMPHIOXUS REFINED AT 2.4 ANGSTROMS RESOLUTION'''<br /> | '''STRUCTURE OF A SARCOPLASMIC CALCIUM-BINDING PROTEIN FROM AMPHIOXUS REFINED AT 2.4 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The three-dimensional structure of a sarcoplasmic Ca(2+)-binding protein | + | The three-dimensional structure of a sarcoplasmic Ca(2+)-binding protein from the protochordate amphioxus has been determined at 2.4 A resolution using multiple-isomorphous-replacement techniques. The refined model includes all 185 residues, three calcium ions, and one water molecule. The final crystallographic R-factor is 0.199. Bond lengths and bond angles in the molecules have root-mean-square deviations from ideal values of 0.015 A and 2.8 degrees, respectively. The overall structure is highly compact and globular with a predominantly hydrophobic core, unlike the extended dumbbell-shaped structures of calmodulin or troponin C. There are four distinct domains with the typical helix-loop-helix Ca(2+)-binding motif (EF hand). The conformation of the pair of EF hands in the N-terminal half of the protein is unusual due to the presence of an aspartate residue in the twelfth position of the first Ca(2+)-binding loop, rather than the usual glutamate. The C-terminal half of the molecule contains one Ca(2+)-binding domain with a novel helix-loop-helix conformation and one Ca(2+)-binding domain that is no longer functional because of amino acid changes. The overall structure is quite similar to a sarcoplasmic Ca(2+)-binding protein from sandworm, although there is only about 12% amino acid sequence identity between them. The similarity of the structures of these two proteins suggests that all sarcoplasmic Ca(2+)-binding proteins will have the same general conformation, even though there is very little conservation of primary structure among the proteins from various species. |
==About this Structure== | ==About this Structure== | ||
| - | 2SAS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Branchiostoma_lanceolatum Branchiostoma lanceolatum] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 2SAS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Branchiostoma_lanceolatum Branchiostoma lanceolatum] 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=2SAS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Branchiostoma lanceolatum]] | [[Category: Branchiostoma lanceolatum]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Babu, Y | + | [[Category: Babu, Y S.]] |
| - | [[Category: Cook, W | + | [[Category: Cook, W J.]] |
| - | [[Category: Cox, J | + | [[Category: Cox, J A.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: calcium-binding protein]] | [[Category: calcium-binding protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:48:59 2008'' |
Revision as of 16:49, 21 February 2008
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STRUCTURE OF A SARCOPLASMIC CALCIUM-BINDING PROTEIN FROM AMPHIOXUS REFINED AT 2.4 ANGSTROMS RESOLUTION
Overview
The three-dimensional structure of a sarcoplasmic Ca(2+)-binding protein from the protochordate amphioxus has been determined at 2.4 A resolution using multiple-isomorphous-replacement techniques. The refined model includes all 185 residues, three calcium ions, and one water molecule. The final crystallographic R-factor is 0.199. Bond lengths and bond angles in the molecules have root-mean-square deviations from ideal values of 0.015 A and 2.8 degrees, respectively. The overall structure is highly compact and globular with a predominantly hydrophobic core, unlike the extended dumbbell-shaped structures of calmodulin or troponin C. There are four distinct domains with the typical helix-loop-helix Ca(2+)-binding motif (EF hand). The conformation of the pair of EF hands in the N-terminal half of the protein is unusual due to the presence of an aspartate residue in the twelfth position of the first Ca(2+)-binding loop, rather than the usual glutamate. The C-terminal half of the molecule contains one Ca(2+)-binding domain with a novel helix-loop-helix conformation and one Ca(2+)-binding domain that is no longer functional because of amino acid changes. The overall structure is quite similar to a sarcoplasmic Ca(2+)-binding protein from sandworm, although there is only about 12% amino acid sequence identity between them. The similarity of the structures of these two proteins suggests that all sarcoplasmic Ca(2+)-binding proteins will have the same general conformation, even though there is very little conservation of primary structure among the proteins from various species.
About this Structure
2SAS is a Single protein structure of sequence from Branchiostoma lanceolatum with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of a sarcoplasmic calcium-binding protein from amphioxus refined at 2.4 A resolution., Cook WJ, Jeffrey LC, Cox JA, Vijay-Kumar S, J Mol Biol. 1993 Jan 20;229(2):461-71. PMID:8429557
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