1mos
From Proteopedia
(New page: 200px<br /><applet load="1mos" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mos, resolution 2.00Å" /> '''ISOMERASE DOMAIN OF ...) |
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| - | [[Image:1mos.gif|left|200px]]<br /><applet load="1mos" size=" | + | [[Image:1mos.gif|left|200px]]<br /><applet load="1mos" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mos, resolution 2.00Å" /> | caption="1mos, resolution 2.00Å" /> | ||
'''ISOMERASE DOMAIN OF GLUCOSAMINE 6-PHOSPHATE SYNTHASE COMPLEXED WITH 2-AMINO-2-DEOXYGLUCITOL 6-PHOSPHATE'''<br /> | '''ISOMERASE DOMAIN OF GLUCOSAMINE 6-PHOSPHATE SYNTHASE COMPLEXED WITH 2-AMINO-2-DEOXYGLUCITOL 6-PHOSPHATE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Glucosamine 6-phosphate synthase converts fructose-6P into glucosamine-6P | + | Glucosamine 6-phosphate synthase converts fructose-6P into glucosamine-6P or glucose-6P depending on the presence or absence of glutamine. The isomerase activity is associated with a 40-kDa C-terminal domain, which has already been characterized crystallographically. Now the three-dimensional structures of the complexes with the reaction product glucose-6P and with the transition state analog 2-amino-2-deoxyglucitol-6P have been determined. Glucose-6P binds in a cyclic form whereas 2-amino-2-deoxyglucitol-6P is in an extended conformation. The information on ligand-protein interactions observed in the crystal structures together with the isotope exchange and site-directed mutagenesis data allow us to propose a mechanism of the isomerase activity of glucosamine-6P synthase. The sugar phosphate isomerization involves a ring opening step catalyzed by His504 and an enolization step with Glu488 catalyzing the hydrogen transfer from C1 to C2 of the substrate. The enediol intermediate is stabilized by a helix dipole and the epsilon-amino group of Lys603. Lys485 may play a role in deprotonating the hydroxyl O1 of the intermediate. |
==About this Structure== | ==About this Structure== | ||
| - | 1MOS 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, NA, AGP and MES as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutamine--fructose-6-phosphate_transaminase_(isomerizing) Glutamine--fructose-6-phosphate transaminase (isomerizing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.16 2.6.1.16] Full crystallographic information is available from [http:// | + | 1MOS 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>, <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=AGP:'>AGP</scene> and <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutamine--fructose-6-phosphate_transaminase_(isomerizing) Glutamine--fructose-6-phosphate transaminase (isomerizing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.16 2.6.1.16] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MOS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Badet, B.]] | [[Category: Badet, B.]] | ||
| - | [[Category: Badet-Denisot, M | + | [[Category: Badet-Denisot, M A.]] |
[[Category: Obmolova, G.]] | [[Category: Obmolova, G.]] | ||
[[Category: Teplyakov, A.]] | [[Category: Teplyakov, A.]] | ||
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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 13:57:25 2008'' |
Revision as of 11:57, 21 February 2008
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ISOMERASE DOMAIN OF GLUCOSAMINE 6-PHOSPHATE SYNTHASE COMPLEXED WITH 2-AMINO-2-DEOXYGLUCITOL 6-PHOSPHATE
Overview
Glucosamine 6-phosphate synthase converts fructose-6P into glucosamine-6P or glucose-6P depending on the presence or absence of glutamine. The isomerase activity is associated with a 40-kDa C-terminal domain, which has already been characterized crystallographically. Now the three-dimensional structures of the complexes with the reaction product glucose-6P and with the transition state analog 2-amino-2-deoxyglucitol-6P have been determined. Glucose-6P binds in a cyclic form whereas 2-amino-2-deoxyglucitol-6P is in an extended conformation. The information on ligand-protein interactions observed in the crystal structures together with the isotope exchange and site-directed mutagenesis data allow us to propose a mechanism of the isomerase activity of glucosamine-6P synthase. The sugar phosphate isomerization involves a ring opening step catalyzed by His504 and an enolization step with Glu488 catalyzing the hydrogen transfer from C1 to C2 of the substrate. The enediol intermediate is stabilized by a helix dipole and the epsilon-amino group of Lys603. Lys485 may play a role in deprotonating the hydroxyl O1 of the intermediate.
About this Structure
1MOS is a Single protein structure of sequence from Escherichia coli with , , and as ligands. Active as Glutamine--fructose-6-phosphate transaminase (isomerizing), with EC number 2.6.1.16 Full crystallographic information is available from OCA.
Reference
The mechanism of sugar phosphate isomerization by glucosamine 6-phosphate synthase., Teplyakov A, Obmolova G, Badet-Denisot MA, Badet B, Protein Sci. 1999 Mar;8(3):596-602. PMID:10091662
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