2j6h: Difference between revisions
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==Overview== | ==Overview== | ||
Glucosamine-6P synthase catalyzes the synthesis of glucosamine-6P from | Glucosamine-6P synthase catalyzes the synthesis of glucosamine-6P from fructose-6P and glutamine and uses a channel to transfer ammonia from its glutaminase to its synthase active site. X-ray structures of glucosamine-6P synthase have been determined at 2.05 Angstroms resolution in the presence of fructose-6P and at 2.35 Angstroms resolution in the presence of fructose-6P and 6-diazo-5-oxo-L-norleucine, a glutamine affinity analog that covalently modifies the N-terminal catalytic cysteine, therefore mimicking the gamma-glutamyl-thioester intermediate formed during hydrolysis of glutamine. The fixation of the glutamine analog activates the enzyme through several major structural changes: 1) the closure of a loop to shield the glutaminase site accompanied by significant domain hinging, 2) the activation of catalytic residues involved in glutamine hydrolysis, i.e. the alpha-amino group of Cys-1 and Asn-98 that is positioned to form the oxyanion hole, and 3) a 75 degrees rotation of the Trp-74 indole group that opens the ammonia channel. | ||
==About this Structure== | ==About this Structure== | ||
2J6H 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=G6Q:'>G6Q</scene> and <scene name='pdbligand=ONL:'>ONL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure | 2J6H 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=G6Q:'>G6Q</scene> and <scene name='pdbligand=ONL:'>ONL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure supersedes the now removed PDB entry 2BPJ. 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] Known structural/functional Site: <scene name='pdbsite=AC1:G6q+Binding+Site+For+Chain+B'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2J6H OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
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Revision as of 15:59, 21 February 2008
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E. COLI GLUCOSAMINE-6-P SYNTHASE IN COMPLEX WITH GLUCOSE-6P AND 5-OXO-L-NORLEUCINE
Overview
Glucosamine-6P synthase catalyzes the synthesis of glucosamine-6P from fructose-6P and glutamine and uses a channel to transfer ammonia from its glutaminase to its synthase active site. X-ray structures of glucosamine-6P synthase have been determined at 2.05 Angstroms resolution in the presence of fructose-6P and at 2.35 Angstroms resolution in the presence of fructose-6P and 6-diazo-5-oxo-L-norleucine, a glutamine affinity analog that covalently modifies the N-terminal catalytic cysteine, therefore mimicking the gamma-glutamyl-thioester intermediate formed during hydrolysis of glutamine. The fixation of the glutamine analog activates the enzyme through several major structural changes: 1) the closure of a loop to shield the glutaminase site accompanied by significant domain hinging, 2) the activation of catalytic residues involved in glutamine hydrolysis, i.e. the alpha-amino group of Cys-1 and Asn-98 that is positioned to form the oxyanion hole, and 3) a 75 degrees rotation of the Trp-74 indole group that opens the ammonia channel.
About this Structure
2J6H is a Single protein structure of sequence from Escherichia coli with G6Q and ONL as ligands. This structure supersedes the now removed PDB entry 2BPJ. Active as Glutamine--fructose-6-phosphate transaminase (isomerizing), with EC number 2.6.1.16 Known structural/functional Site: AC1. Full crystallographic information is available from OCA.
Reference
Glutamine binding opens the ammonia channel and activates glucosamine-6P synthase., Mouilleron S, Badet-Denisot MA, Golinelli-Pimpaneau B, J Biol Chem. 2006 Feb 17;281(7):4404-12. Epub 2005 Dec 9. PMID:16339762
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Proteopedia Page Contributors and Editors (what is this?)
- Pages with broken file links
- Escherichia coli
- Glutamine--fructose-6-phosphate transaminase (isomerizing)
- Single protein
- Golinelli-Pimpaneau, B.
- Mouilleron, S.
- G6Q
- ONL
- 5-oxo-l-norleucine
- Amidotransferase
- Aminotransferase
- Ammonia channeling
- Direct protein sequencing
- Glucosamine 6-phosphate synthase
- Glucose 6-phosphate
- Glutamine amidotransferase
- N terminal nucleophile
- Transferase
