Download MendeleyStructural basis for allosteric control of the transcription regulator CcpA by the phosphoprotein HPr-Ser46-P.
Schumacher, M.A., Allen, G.S., Diel, M., Seidel, G., Hillen, W., Brennan, R.G.(2004) Cell 118: 731-741
- PubMed: 15369672 Search on PubMed
- DOI: https://doi.org/10.1016/j.cell.2004.08.027
- Primary Citation Related Structures:
1RZR, 1SXG, 1SXH, 1SXI - PubMed Abstract:
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.
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland 97239, USA.
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