1sxh
From Proteopedia
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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
Page seeded by OCA on Wed Nov 21 02:49:04 2007
