1sxh
From Proteopedia
(New page: 200px<br /><applet load="1sxh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1sxh, resolution 2.75Å" /> '''apo structure of B. ...) |
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| - | [[Image:1sxh.gif|left|200px]]<br /><applet load="1sxh" size=" | + | [[Image:1sxh.gif|left|200px]]<br /><applet load="1sxh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1sxh, resolution 2.75Å" /> | caption="1sxh, resolution 2.75Å" /> | ||
'''apo structure of B. megaterium transcription regulator'''<br /> | '''apo structure of B. megaterium transcription regulator'''<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== | ||
| - | 1SXH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium]. Full crystallographic information is available from [http:// | + | 1SXH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SXH 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: 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 15:06:31 2008'' |
Revision as of 13:06, 21 February 2008
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apo structure of B. megaterium transcription regulator
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
1SXH is a Single protein structure of sequence from Bacillus megaterium. 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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