1d5w
From Proteopedia
(New page: 200px<br /><applet load="1d5w" size="450" color="white" frame="true" align="right" spinBox="true" caption="1d5w, resolution 2.30Å" /> '''PHOSPHORYLATED FIXJ ...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1d5w.gif|left|200px]]<br /><applet load="1d5w" size=" | + | [[Image:1d5w.gif|left|200px]]<br /><applet load="1d5w" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1d5w, resolution 2.30Å" /> | caption="1d5w, resolution 2.30Å" /> | ||
'''PHOSPHORYLATED FIXJ RECEIVER DOMAIN'''<br /> | '''PHOSPHORYLATED FIXJ RECEIVER DOMAIN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: A variety of bacterial adaptative cellular responses to | + | BACKGROUND: A variety of bacterial adaptative cellular responses to environmental stimuli are mediated by two-component signal transduction pathways. In these phosphorelay cascades, histidine kinases transphosphorylate a conserved aspartate in the receiver domain, a conserved module in the response regulator superfamily. The main effect of this phosphorylation is to alter the conformation of the response regulator in order to modulate its biological function. The response regulator FixJ displays a typical modular arrangement, with a phosphorylatable N-terminal receiver domain and a C-terminal DNA-binding domain. In the symbiotic bacterium Sinorhizobium meliloti, phosphorylation of this response regulator activates transcription of nitrogen-fixation genes. RESULTS: The crystal structures of the phosphorylated and of the unphosphorylated N-terminal receiver domain of FixJ (FixJN) were solved at 2.3 A and 2.4 A resolution, respectively. They reveal the environment of the phosphoaspartate in the active site and the specific conformational changes leading to activation of the response regulator. Phosphorylation of the conserved aspartate induces major structural changes in the beta 4-alpha 4 loop, and in the signaling surface alpha 4-beta 5 that mediates dimerization of the phosphorylated full-length response regulator. A site-directed mutant at this protein-protein interface decreases the affinity of the phosphorylated response regulator for the fixK promoter tenfold. CONCLUSIONS: The cascade of phosphorylation-induced conformational changes in FixJN illustrates the role of conserved residues in stabilizing the phosphoryl group in the active site, triggering the structural transition and achieving the post-phosphorylation signaling events. We propose that these phosphorylation-induced conformational changes underly the activation of response regulators in general. |
==About this Structure== | ==About this Structure== | ||
| - | 1D5W is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1D5W is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti] 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=1D5W OCA]. |
==Reference== | ==Reference== | ||
| Line 19: | Line 19: | ||
[[Category: Mourey, L.]] | [[Category: Mourey, L.]] | ||
[[Category: Rousseau, P.]] | [[Category: Rousseau, P.]] | ||
| - | [[Category: Samama, J | + | [[Category: Samama, J P.]] |
[[Category: Schumacher, J.]] | [[Category: Schumacher, J.]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
| Line 26: | Line 26: | ||
[[Category: phosphorylated protein]] | [[Category: phosphorylated protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:13:16 2008'' |
Revision as of 10:13, 21 February 2008
|
PHOSPHORYLATED FIXJ RECEIVER DOMAIN
Overview
BACKGROUND: A variety of bacterial adaptative cellular responses to environmental stimuli are mediated by two-component signal transduction pathways. In these phosphorelay cascades, histidine kinases transphosphorylate a conserved aspartate in the receiver domain, a conserved module in the response regulator superfamily. The main effect of this phosphorylation is to alter the conformation of the response regulator in order to modulate its biological function. The response regulator FixJ displays a typical modular arrangement, with a phosphorylatable N-terminal receiver domain and a C-terminal DNA-binding domain. In the symbiotic bacterium Sinorhizobium meliloti, phosphorylation of this response regulator activates transcription of nitrogen-fixation genes. RESULTS: The crystal structures of the phosphorylated and of the unphosphorylated N-terminal receiver domain of FixJ (FixJN) were solved at 2.3 A and 2.4 A resolution, respectively. They reveal the environment of the phosphoaspartate in the active site and the specific conformational changes leading to activation of the response regulator. Phosphorylation of the conserved aspartate induces major structural changes in the beta 4-alpha 4 loop, and in the signaling surface alpha 4-beta 5 that mediates dimerization of the phosphorylated full-length response regulator. A site-directed mutant at this protein-protein interface decreases the affinity of the phosphorylated response regulator for the fixK promoter tenfold. CONCLUSIONS: The cascade of phosphorylation-induced conformational changes in FixJN illustrates the role of conserved residues in stabilizing the phosphoryl group in the active site, triggering the structural transition and achieving the post-phosphorylation signaling events. We propose that these phosphorylation-induced conformational changes underly the activation of response regulators in general.
About this Structure
1D5W is a Single protein structure of sequence from Sinorhizobium meliloti with as ligand. Full crystallographic information is available from OCA.
Reference
Conformational changes induced by phosphorylation of the FixJ receiver domain., Birck C, Mourey L, Gouet P, Fabry B, Schumacher J, Rousseau P, Kahn D, Samama JP, Structure. 1999 Dec 15;7(12):1505-15. PMID:10647181
Page seeded by OCA on Thu Feb 21 12:13:16 2008
