1c9o
From Proteopedia
(New page: 200px<br /><applet load="1c9o" size="450" color="white" frame="true" align="right" spinBox="true" caption="1c9o, resolution 1.17Å" /> '''CRYSTAL STRUCTURE AN...) |
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| - | [[Image:1c9o.jpg|left|200px]]<br /><applet load="1c9o" size=" | + | [[Image:1c9o.jpg|left|200px]]<br /><applet load="1c9o" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1c9o, resolution 1.17Å" /> | caption="1c9o, resolution 1.17Å" /> | ||
'''CRYSTAL STRUCTURE ANALYSIS OF THE BACILLUS CALDOLYTICUS COLD SHOCK PROTEIN BC-CSP'''<br /> | '''CRYSTAL STRUCTURE ANALYSIS OF THE BACILLUS CALDOLYTICUS COLD SHOCK PROTEIN BC-CSP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The bacterial cold shock proteins are small compact beta-barrel proteins | + | The bacterial cold shock proteins are small compact beta-barrel proteins without disulfide bonds, cis-proline residues or tightly bound cofactors. Bc-Csp, the cold shock protein from the thermophile Bacillus caldolyticus shows a twofold increase in the free energy of stabilization relative to its homolog Bs-CspB from the mesophile Bacillus subtilis, although the two proteins differ by only 12 out of 67 amino acid residues. This pair of cold shock proteins thus represents a good system to study the atomic determinants of protein thermostability. Bs-CspB and Bc-Csp both unfold reversibly in cooperative transitions with T(M) values of 49.0 degrees C and 77.3 degrees C, respectively, at pH 7.0. Addition of 0.5 M salt stabilizes Bs-CspB but destabilizes Bc-Csp. To understand these differences at the structural level, the crystal structure of Bc-Csp was determined at 1.17 A resolution and refined to R=12.5% (R(free)=17.9%). The molecular structures of Bc-Csp and Bs-CspB are virtually identical in the central beta-sheet and in the binding region for nucleic acids. Significant differences are found in the distribution of surface charges including a sodium ion binding site present in Bc-Csp, which was not observed in the crystal structure of the Bs-CspB. Electrostatic interactions are overall favorable for Bc-Csp, but unfavorable for Bs-CspB. They provide the major source for the increased thermostability of Bc-Csp. This can be explained based on the atomic-resolution crystal structure of Bc-Csp. It identifies a number of potentially stabilizing ionic interactions including a cation-binding site and reveals significant changes in the electrostatic surface potential. |
==About this Structure== | ==About this Structure== | ||
| - | 1C9O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_caldolyticus Bacillus caldolyticus] with NA and TRS as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1C9O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_caldolyticus Bacillus caldolyticus] with <scene name='pdbligand=NA:'>NA</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C9O OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Mueller, U.]] | [[Category: Mueller, U.]] | ||
[[Category: Perl, D.]] | [[Category: Perl, D.]] | ||
| - | [[Category: Schmid, F | + | [[Category: Schmid, F X.]] |
[[Category: NA]] | [[Category: NA]] | ||
[[Category: TRS]] | [[Category: TRS]] | ||
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[[Category: homodimer]] | [[Category: homodimer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:03:53 2008'' |
Revision as of 10:03, 21 February 2008
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CRYSTAL STRUCTURE ANALYSIS OF THE BACILLUS CALDOLYTICUS COLD SHOCK PROTEIN BC-CSP
Overview
The bacterial cold shock proteins are small compact beta-barrel proteins without disulfide bonds, cis-proline residues or tightly bound cofactors. Bc-Csp, the cold shock protein from the thermophile Bacillus caldolyticus shows a twofold increase in the free energy of stabilization relative to its homolog Bs-CspB from the mesophile Bacillus subtilis, although the two proteins differ by only 12 out of 67 amino acid residues. This pair of cold shock proteins thus represents a good system to study the atomic determinants of protein thermostability. Bs-CspB and Bc-Csp both unfold reversibly in cooperative transitions with T(M) values of 49.0 degrees C and 77.3 degrees C, respectively, at pH 7.0. Addition of 0.5 M salt stabilizes Bs-CspB but destabilizes Bc-Csp. To understand these differences at the structural level, the crystal structure of Bc-Csp was determined at 1.17 A resolution and refined to R=12.5% (R(free)=17.9%). The molecular structures of Bc-Csp and Bs-CspB are virtually identical in the central beta-sheet and in the binding region for nucleic acids. Significant differences are found in the distribution of surface charges including a sodium ion binding site present in Bc-Csp, which was not observed in the crystal structure of the Bs-CspB. Electrostatic interactions are overall favorable for Bc-Csp, but unfavorable for Bs-CspB. They provide the major source for the increased thermostability of Bc-Csp. This can be explained based on the atomic-resolution crystal structure of Bc-Csp. It identifies a number of potentially stabilizing ionic interactions including a cation-binding site and reveals significant changes in the electrostatic surface potential.
About this Structure
1C9O is a Single protein structure of sequence from Bacillus caldolyticus with and as ligands. Full crystallographic information is available from OCA.
Reference
Thermal stability and atomic-resolution crystal structure of the Bacillus caldolyticus cold shock protein., Mueller U, Perl D, Schmid FX, Heinemann U, J Mol Biol. 2000 Apr 7;297(4):975-88. PMID:10736231
Page seeded by OCA on Thu Feb 21 12:03:53 2008
Categories: Bacillus caldolyticus | Single protein | Heinemann, U. | Mueller, U. | Perl, D. | Schmid, F X. | NA | TRS | Beta barrel | Homodimer
