2oen: Difference between revisions
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[[Image:2oen.jpg|left|200px]] | [[Image:2oen.jpg|left|200px]] | ||
'''Structural mechanism for the fine-tuning of CcpA function by the small molecule effectors glucose-6-phosphate and fructose-1,6-bisphosphate''' | {{Structure | ||
|PDB= 2oen |SIZE=350|CAPTION= <scene name='initialview01'>2oen</scene>, resolution 3.17Å | |||
|SITE= | |||
|LIGAND= | |||
|ACTIVITY= | |||
|GENE= ccpA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1404 Bacillus megaterium]), ptsH ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1404 Bacillus megaterium]) | |||
}} | |||
'''Structural mechanism for the fine-tuning of CcpA function by the small molecule effectors glucose-6-phosphate and fructose-1,6-bisphosphate''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2OEN is a [ | 2OEN is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OEN OCA]. | ||
==Reference== | ==Reference== | ||
Structural mechanism for the fine-tuning of CcpA function by the small molecule effectors glucose 6-phosphate and fructose 1,6-bisphosphate., Schumacher MA, Seidel G, Hillen W, Brennan RG, J Mol Biol. 2007 May 11;368(4):1042-50. Epub 2007 Feb 27. PMID:[http:// | Structural mechanism for the fine-tuning of CcpA function by the small molecule effectors glucose 6-phosphate and fructose 1,6-bisphosphate., Schumacher MA, Seidel G, Hillen W, Brennan RG, J Mol Biol. 2007 May 11;368(4):1042-50. Epub 2007 Feb 27. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/17376479 17376479] | ||
[[Category: Bacillus megaterium]] | [[Category: Bacillus megaterium]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: protein-dna]] | [[Category: protein-dna]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 17:58:46 2008'' | ||
Revision as of 18:58, 20 March 2008
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| , resolution 3.17Å | |||||||
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| Gene: | ccpA (Bacillus megaterium), ptsH (Bacillus megaterium) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structural mechanism for the fine-tuning of CcpA function by the small molecule effectors glucose-6-phosphate and fructose-1,6-bisphosphate
OverviewOverview
In Gram-positive bacteria, carbon catabolite regulation (CCR) is mediated by the carbon catabolite control protein A (CcpA), a member of the LacI-GalR family of transcription regulators. Unlike other LacI-GalR proteins, CcpA is activated to bind DNA by binding the phosphoproteins HPr-Ser46-P or Crh-Ser46-P. However, fine regulation of CCR is accomplished by the small molecule effectors, glucose 6-phosphate (G6P) and fructose 1,6-bisphosphate (FBP), which somehow enhance CcpA-(HPr-Ser46-P) binding to DNA. Unlike the CcpA-(HPr-Ser46-P) complex, DNA binding by CcpA-(Crh-Ser46-P) is not stimulated by G6P or FBP. To understand the fine-tuning mechanism of these effectors, we solved the structures of the CcpA core, DeltaCcpA, which lacks the N-terminal DNA-binding domain, in complex with HPr-Ser46-P and G6P or FBP. G6P and FBP bind in a deep cleft, between the N and C subdomains of CcpA. Neither interacts with HPr-Ser46-P. This suggests that one role of the adjunct corepressors is to buttress the DNA-binding conformation effected by the binding of HPr-Ser46-P to the CcpA dimer N subdomains. However, the structures reveal that an unexpected function of adjunct corepressor binding is to bolster cross interactions between HPr-Ser46-P residue Arg17 and residues Asp69 and Asp99 of the other CcpA subunit. These cross contacts, which are weak or not present in the CcpA-(Crh-Ser46-P) complex, stimulate the CcpA-(HPr-Ser46-P)-DNA interaction specifically. Thus, stabilization of the closed conformation and bolstering of cross contacts between CcpA and its other corepressor, HPr-Ser46-P, provide a molecular explanation for how adjunct corepressors G6P and FBP enhance the interaction between CcpA-(HPr-Ser46-P) and cognate DNA.
About this StructureAbout this Structure
2OEN is a Protein complex structure of sequences from Bacillus megaterium. Full crystallographic information is available from OCA.
ReferenceReference
Structural mechanism for the fine-tuning of CcpA function by the small molecule effectors glucose 6-phosphate and fructose 1,6-bisphosphate., Schumacher MA, Seidel G, Hillen W, Brennan RG, J Mol Biol. 2007 May 11;368(4):1042-50. Epub 2007 Feb 27. PMID:17376479
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