1mb0
From Proteopedia
(New page: 200px<br /><applet load="1mb0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mb0, resolution 2.00Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1mb0.gif|left|200px]]<br /><applet load="1mb0" size=" | + | [[Image:1mb0.gif|left|200px]]<br /><applet load="1mb0" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mb0, resolution 2.00Å" /> | caption="1mb0, resolution 2.00Å" /> | ||
'''CRYSTAL STRUCTURE OF THE RESPONSE REGULATOR DIVK AT PH 8.0 IN COMPLEX WITH MN2+'''<br /> | '''CRYSTAL STRUCTURE OF THE RESPONSE REGULATOR DIVK AT PH 8.0 IN COMPLEX WITH MN2+'''<br /> | ||
==Overview== | ==Overview== | ||
| - | DivK is an essential response regulator in the Gram-negative bacterium | + | DivK is an essential response regulator in the Gram-negative bacterium Caulobacter crescentus and functions in a complex phosphorelay system that precisely controls the sequence of developmental events during the cell division cycle. Structure determinations of this single domain response regulator at different pH values demonstrated that the five-stranded alpha/beta fold of the DivK protein is fully defined only at acidic pH. The crystal structures of the apoprotein and of metal-bound DivK complexes at higher pH values revealed a synergistic pH- and cation binding-induced flexibility of the beta4-alpha4 loop and of the alpha4 helix. This motion increases the solvent accessibility of the single cysteine residue in the protein. Solution state studies demonstrated a 200-fold pH-dependent increase in the affinity of manganese for the protein between pH 6.0 and 8.5 that seems to involve deprotonation of an acido-basic couple. Taken together, these results suggest that flexibility of critical regions of the protein, ionization of the cysteine 99 residue and improved K(D) values for the catalytic metal ion are coupled events. We propose that the molecular events observed in the isolated protein may be required for DivK activation and that they may be achieved in vivo through the specific protein-protein interactions between the response regulator and its cognate kinases. |
==About this Structure== | ==About this Structure== | ||
| - | 1MB0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Caulobacter_vibrioides Caulobacter vibrioides] with MN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1MB0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Caulobacter_vibrioides Caulobacter vibrioides] with <scene name='pdbligand=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MB0 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Newton, A.]] | [[Category: Newton, A.]] | ||
[[Category: Ohta, N.]] | [[Category: Ohta, N.]] | ||
| - | [[Category: SPINE, Structural | + | [[Category: SPINE, Structural Proteomics in Europe.]] |
[[Category: Samama, J-P.]] | [[Category: Samama, J-P.]] | ||
[[Category: MN]] | [[Category: MN]] | ||
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[[Category: structural proteomics in europe]] | [[Category: structural proteomics in europe]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:53:22 2008'' |
Revision as of 11:53, 21 February 2008
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CRYSTAL STRUCTURE OF THE RESPONSE REGULATOR DIVK AT PH 8.0 IN COMPLEX WITH MN2+
Overview
DivK is an essential response regulator in the Gram-negative bacterium Caulobacter crescentus and functions in a complex phosphorelay system that precisely controls the sequence of developmental events during the cell division cycle. Structure determinations of this single domain response regulator at different pH values demonstrated that the five-stranded alpha/beta fold of the DivK protein is fully defined only at acidic pH. The crystal structures of the apoprotein and of metal-bound DivK complexes at higher pH values revealed a synergistic pH- and cation binding-induced flexibility of the beta4-alpha4 loop and of the alpha4 helix. This motion increases the solvent accessibility of the single cysteine residue in the protein. Solution state studies demonstrated a 200-fold pH-dependent increase in the affinity of manganese for the protein between pH 6.0 and 8.5 that seems to involve deprotonation of an acido-basic couple. Taken together, these results suggest that flexibility of critical regions of the protein, ionization of the cysteine 99 residue and improved K(D) values for the catalytic metal ion are coupled events. We propose that the molecular events observed in the isolated protein may be required for DivK activation and that they may be achieved in vivo through the specific protein-protein interactions between the response regulator and its cognate kinases.
About this Structure
1MB0 is a Single protein structure of sequence from Caulobacter vibrioides with as ligand. Full crystallographic information is available from OCA.
Reference
Crystallographic and biochemical studies of DivK reveal novel features of an essential response regulator in Caulobacter crescentus., Guillet V, Ohta N, Cabantous S, Newton A, Samama JP, J Biol Chem. 2002 Nov 1;277(44):42003-10. Epub 2002 Aug 10. PMID:12176983
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