2bih
From Proteopedia
(New page: 200px<br /><applet load="2bih" size="450" color="white" frame="true" align="right" spinBox="true" caption="2bih, resolution 2.600Å" /> '''CRYSTAL STRUCTURE O...) |
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| - | [[Image:2bih.gif|left|200px]]<br /><applet load="2bih" size=" | + | [[Image:2bih.gif|left|200px]]<br /><applet load="2bih" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2bih, resolution 2.600Å" /> | caption="2bih, resolution 2.600Å" /> | ||
'''CRYSTAL STRUCTURE OF THE MOLYBDENUM-CONTAINING NITRATE REDUCING FRAGMENT OF PICHIA ANGUSTA ASSIMILATORY NITRATE REDUCTASE'''<br /> | '''CRYSTAL STRUCTURE OF THE MOLYBDENUM-CONTAINING NITRATE REDUCING FRAGMENT OF PICHIA ANGUSTA ASSIMILATORY NITRATE REDUCTASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Nitrate assimilation in autotrophs provides most of the reduced nitrogen | + | Nitrate assimilation in autotrophs provides most of the reduced nitrogen on earth. In eukaryotes, reduction of nitrate to nitrite is catalyzed by the molybdenum-containing NAD(P)H:nitrate reductase (NR; EC 1.7.1.1-3). In addition to the molybdenum center, NR contains iron-heme and flavin adenine dinucleotide as redox cofactors involved in an internal electron transport chain from NAD(P)H to nitrate. Recombinant, catalytically active Pichia angusta nitrate-reducing, molybdenum-containing fragment (NR-Mo) was expressed in P. pastoris and purified. Crystal structures for NR-Mo were determined at 1.7 and 2.6 angstroms. These structures revealed a unique slot for binding nitrate in the active site and identified key Arg and Trp residues potentially involved in nitrate binding. Dimeric NR-Mo is similar in overall structure to sulfite oxidases, with significant differences in the active site. Sulfate bound in the active site caused conformational changes, as compared with the unbound enzyme. Four ordered water molecules located in close proximity to Mo define a nitrate binding site, a penta-coordinated reaction intermediate, and product release. Because yeast NAD(P)H:NR is representative of the family of eukaryotic NR, we propose a general mechanism for nitrate reduction catalysis. |
==About this Structure== | ==About this Structure== | ||
| - | 2BIH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pichia_angusta Pichia angusta] with MTV as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Nitrate_reductase_(NAD(P)H) Nitrate reductase (NAD(P)H)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.1.2 1.7.1.2] Full crystallographic information is available from [http:// | + | 2BIH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pichia_angusta Pichia angusta] with <scene name='pdbligand=MTV:'>MTV</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Nitrate_reductase_(NAD(P)H) Nitrate reductase (NAD(P)H)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.1.2 1.7.1.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BIH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Barbier, G.]] | [[Category: Barbier, G.]] | ||
| - | [[Category: Campbell, W | + | [[Category: Campbell, W H.]] |
[[Category: Fischer, K.]] | [[Category: Fischer, K.]] | ||
| - | [[Category: Hecht, H | + | [[Category: Hecht, H J.]] |
| - | [[Category: Mendel, R | + | [[Category: Mendel, R R.]] |
[[Category: Schwarz, G.]] | [[Category: Schwarz, G.]] | ||
[[Category: MTV]] | [[Category: MTV]] | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:38:11 2008'' |
Revision as of 14:38, 21 February 2008
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CRYSTAL STRUCTURE OF THE MOLYBDENUM-CONTAINING NITRATE REDUCING FRAGMENT OF PICHIA ANGUSTA ASSIMILATORY NITRATE REDUCTASE
Overview
Nitrate assimilation in autotrophs provides most of the reduced nitrogen on earth. In eukaryotes, reduction of nitrate to nitrite is catalyzed by the molybdenum-containing NAD(P)H:nitrate reductase (NR; EC 1.7.1.1-3). In addition to the molybdenum center, NR contains iron-heme and flavin adenine dinucleotide as redox cofactors involved in an internal electron transport chain from NAD(P)H to nitrate. Recombinant, catalytically active Pichia angusta nitrate-reducing, molybdenum-containing fragment (NR-Mo) was expressed in P. pastoris and purified. Crystal structures for NR-Mo were determined at 1.7 and 2.6 angstroms. These structures revealed a unique slot for binding nitrate in the active site and identified key Arg and Trp residues potentially involved in nitrate binding. Dimeric NR-Mo is similar in overall structure to sulfite oxidases, with significant differences in the active site. Sulfate bound in the active site caused conformational changes, as compared with the unbound enzyme. Four ordered water molecules located in close proximity to Mo define a nitrate binding site, a penta-coordinated reaction intermediate, and product release. Because yeast NAD(P)H:NR is representative of the family of eukaryotic NR, we propose a general mechanism for nitrate reduction catalysis.
About this Structure
2BIH is a Single protein structure of sequence from Pichia angusta with as ligand. Active as Nitrate reductase (NAD(P)H), with EC number 1.7.1.2 Full crystallographic information is available from OCA.
Reference
Structural basis of eukaryotic nitrate reduction: crystal structures of the nitrate reductase active site., Fischer K, Barbier GG, Hecht HJ, Mendel RR, Campbell WH, Schwarz G, Plant Cell. 2005 Apr;17(4):1167-79. Epub 2005 Mar 16. PMID:15772287
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