1ehc
From Proteopedia
(New page: 200px<br /><applet load="1ehc" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ehc, resolution 2.26Å" /> '''STRUCTURE OF SIGNAL ...) |
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| - | [[Image:1ehc.jpg|left|200px]]<br /><applet load="1ehc" size=" | + | [[Image:1ehc.jpg|left|200px]]<br /><applet load="1ehc" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ehc, resolution 2.26Å" /> | caption="1ehc, resolution 2.26Å" /> | ||
'''STRUCTURE OF SIGNAL TRANSDUCTION PROTEIN CHEY'''<br /> | '''STRUCTURE OF SIGNAL TRANSDUCTION PROTEIN CHEY'''<br /> | ||
==Overview== | ==Overview== | ||
| - | An aspartate to lysine mutation at position 13 of the chemotaxis | + | An aspartate to lysine mutation at position 13 of the chemotaxis regulatory protein CheY causes a constitutive tumbly phenotype when expressed at high copy number in vivo even though the mutant protein is not phosphorylatable. These properties suggest that the D13K mutant adopts the active, signaling conformation of CheY independent of phosphorylation, so knowledge of its structure could explain the activation mechanism of CheY. The x-ray crystallographic structure of the CheY D13K mutant has been solved and refined at 2.3 A resolution to an R-factor of 14.3%. The mutant molecule shows no significant differences in backbone conformation when compared with the wild-type, Mg2+-free structure, but there are localized changes within the active site. The side chain of lysine 13 blocks access to the active site, whereas its epsilon-amino group has no bonding interactions with other groups in the region. Also in the active site, the bond between lysine 109 and aspartate 57 is weakened, and the solvent structure is perturbed. Although the D13K mutant has the inactive conformation in the crystalline form, rearrangements in the active site appear to weaken the overall structure of that region, potentially creating a metastable state of the molecule. If a conformational change is required for signaling by CheY D13K, then it most likely proceeds dynamically, in solution. |
==About this Structure== | ==About this Structure== | ||
| - | 1EHC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1EHC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EHC 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 12:27:45 2008'' |
Revision as of 10:27, 21 February 2008
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STRUCTURE OF SIGNAL TRANSDUCTION PROTEIN CHEY
Overview
An aspartate to lysine mutation at position 13 of the chemotaxis regulatory protein CheY causes a constitutive tumbly phenotype when expressed at high copy number in vivo even though the mutant protein is not phosphorylatable. These properties suggest that the D13K mutant adopts the active, signaling conformation of CheY independent of phosphorylation, so knowledge of its structure could explain the activation mechanism of CheY. The x-ray crystallographic structure of the CheY D13K mutant has been solved and refined at 2.3 A resolution to an R-factor of 14.3%. The mutant molecule shows no significant differences in backbone conformation when compared with the wild-type, Mg2+-free structure, but there are localized changes within the active site. The side chain of lysine 13 blocks access to the active site, whereas its epsilon-amino group has no bonding interactions with other groups in the region. Also in the active site, the bond between lysine 109 and aspartate 57 is weakened, and the solvent structure is perturbed. Although the D13K mutant has the inactive conformation in the crystalline form, rearrangements in the active site appear to weaken the overall structure of that region, potentially creating a metastable state of the molecule. If a conformational change is required for signaling by CheY D13K, then it most likely proceeds dynamically, in solution.
About this Structure
1EHC is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Uncoupled phosphorylation and activation in bacterial chemotaxis. The 2.3 A structure of an aspartate to lysine mutant at position 13 of CheY., Jiang M, Bourret RB, Simon MI, Volz K, J Biol Chem. 1997 May 2;272(18):11850-5. PMID:9115243
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