1qqn
From Proteopedia
(New page: 200px<br /><applet load="1qqn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qqn, resolution 1.90Å" /> '''D206S MUTANT OF BOVI...) |
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| - | [[Image:1qqn.gif|left|200px]]<br /><applet load="1qqn" size=" | + | [[Image:1qqn.gif|left|200px]]<br /><applet load="1qqn" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qqn, resolution 1.90Å" /> | caption="1qqn, resolution 1.90Å" /> | ||
'''D206S MUTANT OF BOVINE 70 KILODALTON HEAT SHOCK PROTEIN'''<br /> | '''D206S MUTANT OF BOVINE 70 KILODALTON HEAT SHOCK PROTEIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | ATP binding induces a conformational change in 70-kDa heat shock proteins | + | ATP binding induces a conformational change in 70-kDa heat shock proteins (Hsp70s) that facilitates release of bound polypeptides. Using the bovine heat shock cognate protein (Hsc70) as a representative of the Hsp70 family, we have characterized the effect of mutations on the coupling between ATP binding and the nucleotide-induced conformational change. Steady-state solution small-angle X-ray scattering and kinetic fluorescence measurements on a 60-kDa fragment of Hsc70 show that point mutations K71M, E175S, D199S, and D206S in the nucleotide binding cleft impair the ability of ATP to induce a conformational change. A secondary mutation in the peptide binding domain, E543K, "rescues" the ATP-induced transition for three of these mutations (E175S/E543K, D199S/E543K, and D206S/E543K) but not for K71M/E543K. Analysis of kinetics of the ATPase cycle confirm that these effects do not result from unexpectedly rapid ATP hydrolysis or slow ATP binding. Crystallographic structures of E175S, D199S, and D206S mutant ATPase fragment proteins show that the mutations do not perturb the tertiary structure of the protein but do significantly alter the protein-ligand interactions, due in part to an apparent charge compensation effect whereby mutating a (probably) negatively charged carboxyl group to a neutral serine displaces a K+ ion from the nucleotide binding cleft in two out of three cases (E175S and D199S but not D206S). |
==About this Structure== | ==About this Structure== | ||
| - | 1QQN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with K, CL, MG, PO4 and ADP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1QQN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=K:'>K</scene>, <scene name='pdbligand=CL:'>CL</scene>, <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=ADP:'>ADP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QQN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Johnson, E | + | [[Category: Johnson, E R.]] |
| - | [[Category: McKay, D | + | [[Category: McKay, D B.]] |
[[Category: ADP]] | [[Category: ADP]] | ||
[[Category: CL]] | [[Category: CL]] | ||
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[[Category: molecular chaperone]] | [[Category: molecular chaperone]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:42:37 2008'' |
Revision as of 12:42, 21 February 2008
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D206S MUTANT OF BOVINE 70 KILODALTON HEAT SHOCK PROTEIN
Overview
ATP binding induces a conformational change in 70-kDa heat shock proteins (Hsp70s) that facilitates release of bound polypeptides. Using the bovine heat shock cognate protein (Hsc70) as a representative of the Hsp70 family, we have characterized the effect of mutations on the coupling between ATP binding and the nucleotide-induced conformational change. Steady-state solution small-angle X-ray scattering and kinetic fluorescence measurements on a 60-kDa fragment of Hsc70 show that point mutations K71M, E175S, D199S, and D206S in the nucleotide binding cleft impair the ability of ATP to induce a conformational change. A secondary mutation in the peptide binding domain, E543K, "rescues" the ATP-induced transition for three of these mutations (E175S/E543K, D199S/E543K, and D206S/E543K) but not for K71M/E543K. Analysis of kinetics of the ATPase cycle confirm that these effects do not result from unexpectedly rapid ATP hydrolysis or slow ATP binding. Crystallographic structures of E175S, D199S, and D206S mutant ATPase fragment proteins show that the mutations do not perturb the tertiary structure of the protein but do significantly alter the protein-ligand interactions, due in part to an apparent charge compensation effect whereby mutating a (probably) negatively charged carboxyl group to a neutral serine displaces a K+ ion from the nucleotide binding cleft in two out of three cases (E175S and D199S but not D206S).
About this Structure
1QQN is a Single protein structure of sequence from Bos taurus with , , , and as ligands. Full crystallographic information is available from OCA.
Reference
Mapping the role of active site residues for transducing an ATP-induced conformational change in the bovine 70-kDa heat shock cognate protein., Johnson ER, McKay DB, Biochemistry. 1999 Aug 17;38(33):10823-30. PMID:10451379
Page seeded by OCA on Thu Feb 21 14:42:37 2008
Categories: Bos taurus | Single protein | Johnson, E R. | McKay, D B. | ADP | CL | K | MG | PO4 | Atpase | Hydrolase (acting on acid anhydrides) | Molecular chaperone
