This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


2ppd

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:2ppd.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:2ppd.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2ppd| PDB=2ppd | SCENE= }}
{{STRUCTURE_2ppd| PDB=2ppd | SCENE= }}
-
'''Oxidized H145A mutant of AfNiR bound to nitric oxide'''
+
===Oxidized H145A mutant of AfNiR bound to nitric oxide===
-
==Overview==
+
<!--
-
Nitrite reductase (NiR) is an enzyme that uses type 1 and type 2 copper sites to reduce nitrite to nitric oxide during bacterial denitrification. A copper-nitrosyl intermediate is a proposed, yet poorly characterized feature of the NiR catalytic cycle. This intermediate is formally described as Cu(I)-NO+ and is proposed to be formed at the type 2 copper site after nitrite binding and electron transfer from the type 1 copper site. In this study, copper-nitrosyl complexes were formed by prolonged exposure of exogenous NO to crystals of wild-type and two variant forms of NiR from Alcaligenes faecalis (AfNiR), and the structures were determined to 1.8 A or better resolution. Exposing oxidized wild-type crystals to NO results in the reverse reaction and formation of nitrite that remains bound at the active site. In a type 1 copper site mutant (H145A) that is incapable of electron transfer to the type 2 site, the reverse reaction is not observed. Instead, in both oxidized and reduced H145A crystals, NO is observed bound in a side-on manner to the type 2 copper. In AfNiR, Asp98 forms hydrogen bonds to both substrate and product bound to the type 2 Cu. In the D98N variant, NO is bound side-on but is more disordered when observed for the wild-type enzyme. The solution EPR spectra of the crystallographically characterized NiR-NO complexes indicate the presence of an oxidized type 2 copper site and thus are interpreted as resulting from stable copper-nitrosyls and formally assigned as Cu(II)-NO-. A reaction scheme in which a second NO molecule is oxidized to nitrite can account for the formation of a Cu(II)-NO- species after exposure of the oxidized H145A variant to NO gas.
+
The line below this paragraph, {{ABSTRACT_PUBMED_17924665}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 17924665 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_17924665}}
==About this Structure==
==About this Structure==
Line 31: Line 35:
[[Category: Nitrite reductase]]
[[Category: Nitrite reductase]]
[[Category: Oxidoreductase]]
[[Category: Oxidoreductase]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 13:34:59 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 05:22:42 2008''

Revision as of 02:22, 28 July 2008

Image:2ppd.png

Template:STRUCTURE 2ppd

Oxidized H145A mutant of AfNiR bound to nitric oxide

Template:ABSTRACT PUBMED 17924665

About this Structure

2PPD is a Single protein structure of sequence from Alcaligenes faecalis. Full crystallographic information is available from OCA.

Reference

Stable copper-nitrosyl formation by nitrite reductase in either oxidation state., Tocheva EI, Rosell FI, Mauk AG, Murphy ME, Biochemistry. 2007 Oct 30;46(43):12366-74. Epub 2007 Oct 9. PMID:17924665

Page seeded by OCA on Mon Jul 28 05:22:42 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2ppd"
Personal tools