2gq1
From Proteopedia
(New page: 200px<br /><applet load="2gq1" size="450" color="white" frame="true" align="right" spinBox="true" caption="2gq1, resolution 1.450Å" /> '''Crystal Structure o...) |
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| - | [[Image:2gq1.gif|left|200px]]<br /><applet load="2gq1" size=" | + | [[Image:2gq1.gif|left|200px]]<br /><applet load="2gq1" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2gq1, resolution 1.450Å" /> | caption="2gq1, resolution 1.450Å" /> | ||
'''Crystal Structure of Recombinant Type I Fructose-1,6-bisphosphatase from Escherichia coli Complexed with Sulfate Ions'''<br /> | '''Crystal Structure of Recombinant Type I Fructose-1,6-bisphosphatase from Escherichia coli Complexed with Sulfate Ions'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Fructose-1,6-bisphosphatase (FBPase) governs a key step in | + | Fructose-1,6-bisphosphatase (FBPase) governs a key step in gluconeogenesis, the conversion of fructose 1,6-bisphosphate into fructose 6-phosphate. In mammals, the enzyme is subject to metabolic regulation, but regulatory mechanisms of bacterial FBPases are not well understood. Presented here is the crystal structure (resolution, 1.45A) of recombinant FBPase from Escherichia coli, the first structure of a prokaryotic Type I FBPase. The E. coli enzyme is a homotetramer, but in a quaternary state between the canonical R- and T-states of porcine FBPase. Phe(15) and residues at the C-terminal side of the first alpha-helix (helix H1) occupy the AMP binding pocket. Residues at the N-terminal side of helix H1 hydrogen bond with sulfate ions buried at a subunit interface, which in porcine FBPase undergoes significant conformational change in response to allosteric effectors. Phosphoenolpyruvate and sulfate activate E. coli FBPase by at least 300%. Key residues that bind sulfate anions are conserved among many heterotrophic bacteria, but are absent in FBPases of organisms that employ fructose 2,6-bisphosphate as a regulator. These observations suggest a new mechanism of regulation in the FBPase enzyme family: anionic ligands, most likely phosphoenolpyruvate, bind to allosteric activator sites, which in turn stabilize a tetramer and a polypeptide fold that obstructs AMP binding. |
==About this Structure== | ==About this Structure== | ||
| - | 2GQ1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Fructose-bisphosphatase Fructose-bisphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.11 3.1.3.11] Full crystallographic information is available from [http:// | + | 2GQ1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Fructose-bisphosphatase Fructose-bisphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.11 3.1.3.11] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GQ1 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Fructose-bisphosphatase]] | [[Category: Fructose-bisphosphatase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Fromm, H | + | [[Category: Fromm, H J.]] |
| - | [[Category: Hines, J | + | [[Category: Hines, J K.]] |
| - | [[Category: Honzatko, R | + | [[Category: Honzatko, R B.]] |
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: allosteric activator site]] | [[Category: allosteric activator site]] | ||
[[Category: quaternary conformation]] | [[Category: quaternary conformation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:34:07 2008'' |
Revision as of 15:34, 21 February 2008
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Crystal Structure of Recombinant Type I Fructose-1,6-bisphosphatase from Escherichia coli Complexed with Sulfate Ions
Overview
Fructose-1,6-bisphosphatase (FBPase) governs a key step in gluconeogenesis, the conversion of fructose 1,6-bisphosphate into fructose 6-phosphate. In mammals, the enzyme is subject to metabolic regulation, but regulatory mechanisms of bacterial FBPases are not well understood. Presented here is the crystal structure (resolution, 1.45A) of recombinant FBPase from Escherichia coli, the first structure of a prokaryotic Type I FBPase. The E. coli enzyme is a homotetramer, but in a quaternary state between the canonical R- and T-states of porcine FBPase. Phe(15) and residues at the C-terminal side of the first alpha-helix (helix H1) occupy the AMP binding pocket. Residues at the N-terminal side of helix H1 hydrogen bond with sulfate ions buried at a subunit interface, which in porcine FBPase undergoes significant conformational change in response to allosteric effectors. Phosphoenolpyruvate and sulfate activate E. coli FBPase by at least 300%. Key residues that bind sulfate anions are conserved among many heterotrophic bacteria, but are absent in FBPases of organisms that employ fructose 2,6-bisphosphate as a regulator. These observations suggest a new mechanism of regulation in the FBPase enzyme family: anionic ligands, most likely phosphoenolpyruvate, bind to allosteric activator sites, which in turn stabilize a tetramer and a polypeptide fold that obstructs AMP binding.
About this Structure
2GQ1 is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Fructose-bisphosphatase, with EC number 3.1.3.11 Full crystallographic information is available from OCA.
Reference
Novel allosteric activation site in Escherichia coli fructose-1,6-bisphosphatase., Hines JK, Fromm HJ, Honzatko RB, J Biol Chem. 2006 Jul 7;281(27):18386-93. Epub 2006 May 2. PMID:16670087
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