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1sxi
From Proteopedia
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[[Image:1sxi.gif|left|200px]] | [[Image:1sxi.gif|left|200px]] | ||
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'''Structure of apo transcription regulator B. megaterium''' | '''Structure of apo transcription regulator B. megaterium''' | ||
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[[Category: Schumacher, M A.]] | [[Category: Schumacher, M A.]] | ||
[[Category: Seidel, G.]] | [[Category: Seidel, G.]] | ||
| - | [[Category: | + | [[Category: Allosterism]] |
| - | [[Category: | + | [[Category: Ccr]] |
| - | [[Category: | + | [[Category: Gram positive bacteria]] |
| - | [[Category: | + | [[Category: Phosphoprotein]] |
| - | [[Category: | + | [[Category: Transcription regulation]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 09:15:02 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 06:15, 3 May 2008
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. 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 Page seeded by OCA on Sat May 3 09:15:02 2008
