2a3t: Difference between revisions
New page: left|200px<br /><applet load="2a3t" size="450" color="white" frame="true" align="right" spinBox="true" caption="2a3t, resolution 1.85Å" /> '''Cu-containing nitrit... |
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[[Image:2a3t.gif|left|200px]]<br /><applet load="2a3t" size=" | [[Image:2a3t.gif|left|200px]]<br /><applet load="2a3t" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2a3t, resolution 1.85Å" /> | caption="2a3t, resolution 1.85Å" /> | ||
'''Cu-containing nitrite reductase'''<br /> | '''Cu-containing nitrite reductase'''<br /> | ||
==Overview== | ==Overview== | ||
Nitrite reductase is an enzyme operating in the denitrification pathway | Nitrite reductase is an enzyme operating in the denitrification pathway which catalyses the conversion of nitrite (NO2(-)) to gaseous nitric oxide (NO). Here, crystal structures of the oxidized and reduced forms of the copper-containing nitrite reductase from Rhodobacter sphaeroides 2.4.3 are presented at 1.74 and 1.85 A resolution, respectively. Whereas the structure of the enzyme is very similar to those of other copper-containing nitrite reductases, folding as a trimer and containing two copper sites per monomer, the structures reported here enable conformational differences between the oxidized and reduced forms of the enzyme to be identified. In the type 1 copper site, a rotational perturbation of the side chain of the copper ligand Met182 occurs upon reduction. At the type 2 copper site, a dual conformation of the catalytic residue His287 is observed in the oxidized structure but is lacking in the reduced structure, such that the interactions of the oxidized type 2 copper ion can be regarded as adopting octahedral geometry. These findings shed light on the structural mechanism of the reduction of a copper-bound nitrite to nitric oxide and water. | ||
==About this Structure== | ==About this Structure== | ||
2A3T is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides] with CU and MG as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitrite_reductase_(NO-forming) Nitrite reductase (NO-forming)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.2.1 1.7.2.1] Full crystallographic information is available from [http:// | 2A3T is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides] with <scene name='pdbligand=CU:'>CU</scene> and <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitrite_reductase_(NO-forming) Nitrite reductase (NO-forming)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.2.1 1.7.2.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A3T OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: nitrite reduction]] | [[Category: nitrite reduction]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:23:18 2008'' | ||
Revision as of 17:23, 21 February 2008
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Cu-containing nitrite reductase
OverviewOverview
Nitrite reductase is an enzyme operating in the denitrification pathway which catalyses the conversion of nitrite (NO2(-)) to gaseous nitric oxide (NO). Here, crystal structures of the oxidized and reduced forms of the copper-containing nitrite reductase from Rhodobacter sphaeroides 2.4.3 are presented at 1.74 and 1.85 A resolution, respectively. Whereas the structure of the enzyme is very similar to those of other copper-containing nitrite reductases, folding as a trimer and containing two copper sites per monomer, the structures reported here enable conformational differences between the oxidized and reduced forms of the enzyme to be identified. In the type 1 copper site, a rotational perturbation of the side chain of the copper ligand Met182 occurs upon reduction. At the type 2 copper site, a dual conformation of the catalytic residue His287 is observed in the oxidized structure but is lacking in the reduced structure, such that the interactions of the oxidized type 2 copper ion can be regarded as adopting octahedral geometry. These findings shed light on the structural mechanism of the reduction of a copper-bound nitrite to nitric oxide and water.
About this StructureAbout this Structure
2A3T is a Single protein structure of sequence from Rhodobacter sphaeroides with and as ligands. Active as Nitrite reductase (NO-forming), with EC number 1.7.2.1 Full crystallographic information is available from OCA.
ReferenceReference
Structures of the oxidized and reduced forms of nitrite reductase from Rhodobacter sphaeroides 2.4.3 at high pH: changes in the interactions of the type 2 copper., Jacobson F, Guo H, Olesen K, Okvist M, Neutze R, Sjolin L, Acta Crystallogr D Biol Crystallogr. 2005 Sep;61(Pt 9):1190-8. Epub 2005, Aug 16. PMID:16131751
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