1ea0
From Proteopedia
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| - | [[Image:1ea0.jpg|left|200px]]<br /><applet load="1ea0" size=" | + | [[Image:1ea0.jpg|left|200px]]<br /><applet load="1ea0" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ea0, resolution 3.0Å" /> | caption="1ea0, resolution 3.0Å" /> | ||
'''ALPHA SUBUNIT OF A. BRASILENSE GLUTAMATE SYNTHASE'''<br /> | '''ALPHA SUBUNIT OF A. BRASILENSE GLUTAMATE SYNTHASE'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1EA0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Azospirillum_brasilense Azospirillum brasilense] with OMT, FMN, AKG and F3S as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutamate_synthase_(NADPH) Glutamate synthase (NADPH)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.4.1.13 1.4.1.13] Known structural/functional Site: <scene name='pdbsite=OMA:F3s Binding Site For Chain B'>OMA</scene>. Full crystallographic information is available from [http:// | + | 1EA0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Azospirillum_brasilense Azospirillum brasilense] with <scene name='pdbligand=OMT:'>OMT</scene>, <scene name='pdbligand=FMN:'>FMN</scene>, <scene name='pdbligand=AKG:'>AKG</scene> and <scene name='pdbligand=F3S:'>F3S</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glutamate_synthase_(NADPH) Glutamate synthase (NADPH)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.4.1.13 1.4.1.13] Known structural/functional Site: <scene name='pdbsite=OMA:F3s+Binding+Site+For+Chain+B'>OMA</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EA0 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: complex iron sulphur flavoprotein]] | [[Category: complex iron sulphur flavoprotein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 09:38:42 2008'' |
Revision as of 07:38, 3 February 2008
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ALPHA SUBUNIT OF A. BRASILENSE GLUTAMATE SYNTHASE
Overview
INTRODUCTION: The complex iron-sulfur flavoprotein glutamate synthase, catalyses the reductive synthesis of L-glutamate from 2-oxoglutarate and, L-glutamine, a reaction in the plant and bacterial pathway for ammonia, assimilation. The enzyme functions through three distinct active centers, carrying out L-glutamine hydrolysis, conversion of 2-oxoglutarate into, L-glutamate, and electron uptake from an electron donor. RESULTS: The 3.0, A crystal structure of the dimeric 324 kDa core protein of a bacterial, glutamate synthase was solved by the MAD method, using the very weak, anomalous signal of the two 3Fe-4S clusters present in the asymmetric, unit. The 1,472 amino acids of the monomer fold into a four-domain, architecture. The two catalytic domains have canonical, Ntn-amidotransferase and FMN binding (beta/alpha)8 barrel folds, respectively. The other two domains have an unusual "cut (beta/alpha)8, barrel" topology and an unexpected novel beta-helix structure. Channeling, of the ammonia intermediate is brought about by an internal tunnel of 31 A, length, which runs from the site of L-glutamine hydrolysis to the site of, L-glutamate synthesis. CONCLUSIONS: The outstanding property of glutamate, synthase is the ability to coordinate the activity of its various, functional sites to avoid wasteful consumption of L-glutamine. The, structure reveals two polypeptide segments that connect the catalytic, centers and embed the ammonia tunnel, thus being ideally suited to, function in interdomain signaling. Depending on the enzyme redox and, ligation states, these signal-transducing elements may affect the active, site geometry and control ammonia diffusion through a gating mechanism.
About this Structure
1EA0 is a Single protein structure of sequence from Azospirillum brasilense with , , and as ligands. Active as Glutamate synthase (NADPH), with EC number 1.4.1.13 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Cross-talk and ammonia channeling between active centers in the unexpected domain arrangement of glutamate synthase., Binda C, Bossi RT, Wakatsuki S, Arzt S, Coda A, Curti B, Vanoni MA, Mattevi A, Structure. 2000 Dec 15;8(12):1299-308. PMID:11188694
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