1sxi
From Proteopedia
(New page: 200px<br /><applet load="1sxi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1sxi, resolution 3.00Å" /> '''Structure of apo tra...) |
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| - | [[Image:1sxi.gif|left|200px]]<br /><applet load="1sxi" size=" | + | [[Image:1sxi.gif|left|200px]]<br /><applet load="1sxi" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1sxi, resolution 3.00Å" /> | caption="1sxi, resolution 3.00Å" /> | ||
'''Structure of apo transcription regulator B. megaterium'''<br /> | '''Structure of apo transcription regulator B. megaterium'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Carbon catabolite repression (CCR) is one of the most fundamental | + | Carbon catabolite repression (CCR) is one of the most fundamental environmental-sensing mechanisms in bacteria and imparts competitive advantage by establishing priorities in carbon metabolism. In gram-positive bacteria, the master transcription regulator of CCR is CcpA. CcpA is a LacI-GalR family member that employs, as an allosteric corepressor, the phosphoprotein HPr-Ser46-P, which is formed in glucose-replete conditions. Here we report structures of the Bacillus megaterium apoCcpA and a CcpA-(HPr-Ser46-P)-DNA complex. These structures reveal that HPr-Ser46-P mediates a novel two-component allosteric DNA binding activation mechanism that involves both rotation of the CcpA subdomains and relocation of pivot-point residue Thr61, which leads to juxtaposition of the DNA binding regions permitting "hinge" helix formation in the presence of cognate DNA. The structure of the CcpA-(HPr-Ser46-P)-cre complex also reveals the elegant mechanism by which CcpA family-specific interactions with HPr-Ser46-P residues Ser46-P and His15 partition the high-energy CCR and low-energy PTS pathways, the latter requiring HPr-His15-P. |
==About this Structure== | ==About this Structure== | ||
| - | 1SXI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium] with MG as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1SXI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium] with <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SXI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bacillus megaterium]] | [[Category: Bacillus megaterium]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Allen, G | + | [[Category: Allen, G S.]] |
| - | [[Category: Brennan, R | + | [[Category: Brennan, R G.]] |
[[Category: Diel, M.]] | [[Category: Diel, M.]] | ||
[[Category: Hillen, W.]] | [[Category: Hillen, W.]] | ||
| - | [[Category: Schumacher, M | + | [[Category: Schumacher, M A.]] |
[[Category: Seidel, G.]] | [[Category: Seidel, G.]] | ||
[[Category: MG]] | [[Category: MG]] | ||
[[Category: allosterism; phosphoprotein; transcription regulation; gram positive bacteria; ccr]] | [[Category: allosterism; phosphoprotein; transcription regulation; gram positive bacteria; ccr]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:06:37 2008'' |
Revision as of 13:06, 21 February 2008
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Structure of apo transcription regulator B. megaterium
Overview
Carbon catabolite repression (CCR) is one of the most fundamental environmental-sensing mechanisms in bacteria and imparts competitive advantage by establishing priorities in carbon metabolism. In gram-positive bacteria, the master transcription regulator of CCR is CcpA. CcpA is a LacI-GalR family member that employs, as an allosteric corepressor, the phosphoprotein HPr-Ser46-P, which is formed in glucose-replete conditions. Here we report structures of the Bacillus megaterium apoCcpA and a CcpA-(HPr-Ser46-P)-DNA complex. These structures reveal that HPr-Ser46-P mediates a novel two-component allosteric DNA binding activation mechanism that involves both rotation of the CcpA subdomains and relocation of pivot-point residue Thr61, which leads to juxtaposition of the DNA binding regions permitting "hinge" helix formation in the presence of cognate DNA. The structure of the CcpA-(HPr-Ser46-P)-cre complex also reveals the elegant mechanism by which CcpA family-specific interactions with HPr-Ser46-P residues Ser46-P and His15 partition the high-energy CCR and low-energy PTS pathways, the latter requiring HPr-His15-P.
About this Structure
1SXI is a Single protein structure of sequence from Bacillus megaterium with as ligand. Full crystallographic information is available from OCA.
Reference
Structural basis for allosteric control of the transcription regulator CcpA by the phosphoprotein HPr-Ser46-P., Schumacher MA, Allen GS, Diel M, Seidel G, Hillen W, Brennan RG, Cell. 2004 Sep 17;118(6):731-41. PMID:15369672
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