1sxi
Structure of apo transcription regulator B. megaterium
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OverviewOverview
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 StructureAbout this Structure
1SXI is a Single protein structure of sequence from Bacillus megaterium with MG as ligand. Full crystallographic information is available from OCA.
ReferenceReference
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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