1udr
From Proteopedia
(New page: 200px<br /><applet load="1udr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1udr, resolution 1.9Å" /> '''CHEY MUTANT WITH LYS ...) |
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| - | [[Image:1udr.gif|left|200px]]<br /><applet load="1udr" size=" | + | [[Image:1udr.gif|left|200px]]<br /><applet load="1udr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1udr, resolution 1.9Å" /> | caption="1udr, resolution 1.9Å" /> | ||
'''CHEY MUTANT WITH LYS 91 REPLACED BY ASP, LYS 92 REPLACED BY ALA, ILE 96 REPLACED BY LYS AND ALA 98 REPLACED BY LEU (STABILIZING MUTATIONS IN HELIX 4)'''<br /> | '''CHEY MUTANT WITH LYS 91 REPLACED BY ASP, LYS 92 REPLACED BY ALA, ILE 96 REPLACED BY LYS AND ALA 98 REPLACED BY LEU (STABILIZING MUTATIONS IN HELIX 4)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The signal transduction protein CheY displays an alpha/beta-parallel | + | The signal transduction protein CheY displays an alpha/beta-parallel polypeptide folding, including a highly unstable helix alpha4 and a strongly charged active site. Helix alpha4 has been shown to adopt various positions and conformations in different crystal structures, suggesting that it is a mobile segment. Furthermore, the instability of this helix is believed to have functional significance because it is involved in protein-protein contacts with the transmitter protein kinase CheA, the target protein FliM and the phosphatase CheZ. The active site of CheY comprises a cluster of three aspartic acid residues and a lysine residue, all of which participate in the binding of the Mg(2+) needed for the protein activation. Two steps were followed to study the activation mechanism of CheY upon phosphorylation: first, we independently substituted the three aspartic acid residues in the active site with alanine; second, several mutations were designed in helix alpha 4, both to increase its level of stability and to improve its packing against the protein core. The structural and thermodynamic analysis of these mutant proteins provides further evidence of the connection between the active-site area and helix alpha 4, and helps to understand how small movements at the active site are transmitted and amplified to the protein surface. |
==About this Structure== | ==About this Structure== | ||
| - | 1UDR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http:// | + | 1UDR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UDR OCA]. |
==Reference== | ==Reference== | ||
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[[Category: signal transduction]] | [[Category: signal transduction]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:23:20 2008'' |
Revision as of 13:23, 21 February 2008
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CHEY MUTANT WITH LYS 91 REPLACED BY ASP, LYS 92 REPLACED BY ALA, ILE 96 REPLACED BY LYS AND ALA 98 REPLACED BY LEU (STABILIZING MUTATIONS IN HELIX 4)
Overview
The signal transduction protein CheY displays an alpha/beta-parallel polypeptide folding, including a highly unstable helix alpha4 and a strongly charged active site. Helix alpha4 has been shown to adopt various positions and conformations in different crystal structures, suggesting that it is a mobile segment. Furthermore, the instability of this helix is believed to have functional significance because it is involved in protein-protein contacts with the transmitter protein kinase CheA, the target protein FliM and the phosphatase CheZ. The active site of CheY comprises a cluster of three aspartic acid residues and a lysine residue, all of which participate in the binding of the Mg(2+) needed for the protein activation. Two steps were followed to study the activation mechanism of CheY upon phosphorylation: first, we independently substituted the three aspartic acid residues in the active site with alanine; second, several mutations were designed in helix alpha 4, both to increase its level of stability and to improve its packing against the protein core. The structural and thermodynamic analysis of these mutant proteins provides further evidence of the connection between the active-site area and helix alpha 4, and helps to understand how small movements at the active site are transmitted and amplified to the protein surface.
About this Structure
1UDR is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Towards understanding a molecular switch mechanism: thermodynamic and crystallographic studies of the signal transduction protein CheY., Sola M, Lopez-Hernandez E, Cronet P, Lacroix E, Serrano L, Coll M, Parraga A, J Mol Biol. 2000 Oct 20;303(2):213-25. PMID:11023787
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