1glf
From Proteopedia
(New page: 200px<br /><applet load="1glf" size="450" color="white" frame="true" align="right" spinBox="true" caption="1glf, resolution 2.62Å" /> '''CRYSTAL STRUCTURES O...) |
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caption="1glf, resolution 2.62Å" /> | caption="1glf, resolution 2.62Å" /> | ||
'''CRYSTAL STRUCTURES OF ESCHERICHIA COLI GLYCEROL KINASE AND THE MUTANT A65T IN AN INACTIVE TETRAMER: CONFORMATIONAL CHANGES AND IMPLICATIONS FOR ALLOSTERIC REGULATION'''<br /> | '''CRYSTAL STRUCTURES OF ESCHERICHIA COLI GLYCEROL KINASE AND THE MUTANT A65T IN AN INACTIVE TETRAMER: CONFORMATIONAL CHANGES AND IMPLICATIONS FOR ALLOSTERIC REGULATION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Glycerol kinase (GK) from Escherichia coli is a | + | BACKGROUND: Glycerol kinase (GK) from Escherichia coli is a velocity-modulated (V system) enzyme that has three allosteric effectors with independent mechanisms: fructose-1,6-bisphosphate (FBP); the phosphocarrier protein IIAGlc; and adenosine nucleotides. The enzyme exists in solution as functional dimers that associate reversibly to form tetramers. GK is a member of a superfamily of ATPases that share a common ATPase domain and are thought to undergo a large conformational change as an intrinsic step in their catalytic cycle. Members of this family include actin, hexokinase and the heat shock protein hsc70. RESULTS: We report here the crystal structures of GK and a mutant of GK (Ala65-->Thr) in complex with glycerol and ADP. Crystals of both enzymes contain the same 222 symmetric tetramer. The functional dimer is identical to that described previously for the IIAGlc-GK complex structure. The tetramer interface is significantly different, however, with a relative 22.3 degrees rotation and 6.34 A translation of one functional dimer. The overall monomer structure is unchanged except for two regions: the IIAGlc-binding site undergoes a structural rearrangement and residues 230-236 become ordered and bind orthophosphate at the tetramer interface. We also report the structure of a second mutant of GK (IIe474-->Asp) in complex with IIAGlc; this complex crystallized isomorphously to the wild type IIAGlc-GK complex. Site-directed mutants of GK with substitutions at the IIAGlc-binding site show significantly altered kinetic and regulatory properties, suggesting that the conformation of the binding site is linked to the regulation of activity. CONCLUSIONS: We conclude that the new tetramer structure presented here is an inactive form of the physiologically relevant tetramer. The structure and location of the orthophosphate-binding site is consistent with it being part of the FBP-binding site. Mutational analysis and the structure of the IIAGlc-GK(IIe474-->Asp) complex suggest the conformational transition of the IIAGlc-binding site to be an essential aspect of IIAGlc regulation. |
==About this Structure== | ==About this Structure== | ||
| - | 1GLF 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 PO4, ADP and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glycerol_kinase Glycerol kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.30 2.7.1.30] Full crystallographic information is available from [http:// | + | 1GLF 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=PO4:'>PO4</scene>, <scene name='pdbligand=ADP:'>ADP</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glycerol_kinase Glycerol kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.30 2.7.1.30] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GLF OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Glycerol kinase]] | [[Category: Glycerol kinase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Bystrom, C | + | [[Category: Bystrom, C E.]] |
| - | [[Category: Faber, H | + | [[Category: Faber, H R.]] |
| - | [[Category: Feese, M | + | [[Category: Feese, M D.]] |
| - | [[Category: Pettigrew, D | + | [[Category: Pettigrew, D W.]] |
| - | [[Category: Remington, S | + | [[Category: Remington, S J.]] |
[[Category: ADP]] | [[Category: ADP]] | ||
[[Category: GOL]] | [[Category: GOL]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:51:28 2008'' |
Revision as of 10:51, 21 February 2008
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CRYSTAL STRUCTURES OF ESCHERICHIA COLI GLYCEROL KINASE AND THE MUTANT A65T IN AN INACTIVE TETRAMER: CONFORMATIONAL CHANGES AND IMPLICATIONS FOR ALLOSTERIC REGULATION
Overview
BACKGROUND: Glycerol kinase (GK) from Escherichia coli is a velocity-modulated (V system) enzyme that has three allosteric effectors with independent mechanisms: fructose-1,6-bisphosphate (FBP); the phosphocarrier protein IIAGlc; and adenosine nucleotides. The enzyme exists in solution as functional dimers that associate reversibly to form tetramers. GK is a member of a superfamily of ATPases that share a common ATPase domain and are thought to undergo a large conformational change as an intrinsic step in their catalytic cycle. Members of this family include actin, hexokinase and the heat shock protein hsc70. RESULTS: We report here the crystal structures of GK and a mutant of GK (Ala65-->Thr) in complex with glycerol and ADP. Crystals of both enzymes contain the same 222 symmetric tetramer. The functional dimer is identical to that described previously for the IIAGlc-GK complex structure. The tetramer interface is significantly different, however, with a relative 22.3 degrees rotation and 6.34 A translation of one functional dimer. The overall monomer structure is unchanged except for two regions: the IIAGlc-binding site undergoes a structural rearrangement and residues 230-236 become ordered and bind orthophosphate at the tetramer interface. We also report the structure of a second mutant of GK (IIe474-->Asp) in complex with IIAGlc; this complex crystallized isomorphously to the wild type IIAGlc-GK complex. Site-directed mutants of GK with substitutions at the IIAGlc-binding site show significantly altered kinetic and regulatory properties, suggesting that the conformation of the binding site is linked to the regulation of activity. CONCLUSIONS: We conclude that the new tetramer structure presented here is an inactive form of the physiologically relevant tetramer. The structure and location of the orthophosphate-binding site is consistent with it being part of the FBP-binding site. Mutational analysis and the structure of the IIAGlc-GK(IIe474-->Asp) complex suggest the conformational transition of the IIAGlc-binding site to be an essential aspect of IIAGlc regulation.
About this Structure
1GLF is a Single protein structure of sequence from Escherichia coli with , and as ligands. Active as Glycerol kinase, with EC number 2.7.1.30 Full crystallographic information is available from OCA.
Reference
Glycerol kinase from Escherichia coli and an Ala65-->Thr mutant: the crystal structures reveal conformational changes with implications for allosteric regulation., Feese MD, Faber HR, Bystrom CE, Pettigrew DW, Remington SJ, Structure. 1998 Nov 15;6(11):1407-18. PMID:9817843
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