|
|
| Line 1: |
Line 1: |
| [[Image:2qvr.jpg|left|200px]] | | {{Seed}} |
| | [[Image:2qvr.png|left|200px]] |
|
| |
|
| <!-- | | <!-- |
| Line 9: |
Line 10: |
| {{STRUCTURE_2qvr| PDB=2qvr | SCENE= }} | | {{STRUCTURE_2qvr| PDB=2qvr | SCENE= }} |
|
| |
|
| '''E. coli Fructose-1,6-bisphosphatase: Citrate, Fru-2,6-P2, and Mg2+ bound'''
| | ===E. coli Fructose-1,6-bisphosphatase: Citrate, Fru-2,6-P2, and Mg2+ bound=== |
|
| |
|
|
| |
|
| ==Overview==
| | <!-- |
| Fructose-1,6-bisphosphatase (FBPase) operates at a control point in mammalian gluconeogenesis, being inhibited synergistically by fructose 2,6-bisphosphate (Fru-2,6-P(2)) and AMP. AMP and Fru-2,6-P(2) bind to allosteric and active sites, respectively, but the mechanism responsible for AMP/Fru-2,6-P(2) synergy is unclear. Demonstrated here for the first time is a global conformational change in porcine FBPase induced by Fru-2,6-P(2) in the absence of AMP. The Fru-2,6-P(2) complex exhibits a subunit pair rotation of 13 degrees from the R-state (compared with the 15 degrees rotation of the T-state AMP complex) with active site loops in the disengaged conformation. A three-state thermodynamic model in which Fru-2,6-P(2) drives a conformational change to a T-like intermediate state can account for AMP/Fru-2,6-P(2) synergism in mammalian FBPases. AMP and Fru-2,6-P(2) are not synergistic inhibitors of the Type I FBPase from Escherichia coli, and consistent with that model, the complex of E. coli FBPase with Fru-2,6-P(2) remains in the R-state with dynamic loops in the engaged conformation. Evidently in porcine FBPase, the actions of AMP at the allosteric site and Fru-2,6-P(2) at the active site displace engaged dynamic loops by distinct mechanisms, resulting in similar quaternary end-states. Conceivably, Type I FBPases from all eukaryotes may undergo similar global conformational changes in response to Fru-2,6-P(2) ligation.
| | The line below this paragraph, {{ABSTRACT_PUBMED_17933867}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 17933867 is the PubMed ID number. |
| | --> |
| | {{ABSTRACT_PUBMED_17933867}} |
|
| |
|
| ==About this Structure== | | ==About this Structure== |
| Line 32: |
Line 36: |
| [[Category: Sugar phosphatase fold]] | | [[Category: Sugar phosphatase fold]] |
| [[Category: Tetramer]] | | [[Category: Tetramer]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 15:46:27 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 07:29:54 2008'' |
