3oqm

structure of ccpa-hpr-ser46p-ackA2 complex

spinqualitylabelsall models 3oqm, resolution 2.96Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3oqm is a 6 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.96Å Ligands: SEP, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CCPA_BACSU Global transcriptional regulator of carbon catabolite repression (CCR) and carbon catabolite activation (CCA), which ensures optimal energy usage under diverse conditions. Interacts with either P-Ser-HPr or P-Ser-Crh, leading to the formation of a complex that binds to DNA at the catabolite-response elements (cre). Binding to DNA allows activation or repression of many different genes and operons. Publication Abstract from PubMed In Gram-positive bacteria, carbon catabolite protein A (CcpA) is the master regulator of carbon catabolite control, which ensures optimal energy usage under diverse conditions. Unlike other LacI-GalR proteins, CcpA is activated for DNA binding by first forming a complex with the phosphoprotein HPr-Ser46-P. Bacillus subtilis CcpA functions as both a transcription repressor and activator and binds to more than 50 operators called catabolite response elements (cres). These sites are highly degenerate with the consensus, WTGNNARCGNWWWCAW. How CcpA-(HPr-Ser46-P) binds such diverse sequences is unclear. To gain insight into this question, we solved the structures of the CcpA-(HPr-Ser46-P) complex bound to three different operators, the synthetic (syn) cre, ackA2 cre and gntR-down cre. Strikingly, the structures show that the CcpA-bound operators display different bend angles, ranging from 31 degrees to 56 degrees . These differences are accommodated by a flexible linkage between the CcpA helix-turn-helix-loop-helix motif and hinge helices, which allows independent docking of these DNA-binding modules. This flexibility coupled with an abundance of non-polar residues capable of non-specific nucleobase interactions permits CcpA-(HPr-Ser46-P) to bind diverse operators. Indeed, biochemical data show that CcpA-(HPr-Ser46-P) binds the three cre sites with similar affinities. Thus, the data reveal properties that license this protein to function as a global transcription regulator. Structures of carbon catabolite protein A-(HPr-Ser46-P) bound to diverse catabolite response element sites reveal the basis for high-affinity binding to degenerate DNA operators.,Schumacher MA, Sprehe M, Bartholomae M, Hillen W, Brennan RG Nucleic Acids Res. 2010 Nov 23. PMID:21106498 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Catabolite control protein 3D structures Phosphocarrier protein HPr 3D structures

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