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.


1pfr

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1pfr.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:1pfr.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1pfr| PDB=1pfr | SCENE= }}
{{STRUCTURE_1pfr| PDB=1pfr | SCENE= }}
-
'''RIBONUCLEOSIDE-DIPHOSPHATE REDUCTASE 1 BETA CHAIN'''
+
===RIBONUCLEOSIDE-DIPHOSPHATE REDUCTASE 1 BETA CHAIN===
-
==Overview==
+
<!--
-
BACKGROUND. Ribonucleotide reductases (RNRs) catalyze the formation of the deoxyribonucleotides that are essential for DNA synthesis. The R2 subunit of Escherichia coli RNR is a homodimer containing one dinuclear iron centre per monomer. A tyrosyl radical is essential for catalysis, and is formed via a reaction in which the reduced, diferrous form of the iron centre activates dioxygen. To help understand the mechanism of oxygen activation, we examined the structure of the diferrous form of R2. RESULTS. The crystal structures of reduced forms of both wild type R2 and a mutant of R2 (Ser211--&gt; Ala) have been determined at 1.7 A and 2.2 A resolution, respectively. The diferrous iron centre was compared to the previously determined structure of the oxidized, diferric form of R2. In both forms of R2 the iron centre is coordinated by the same carboxylate dominated ligand sphere, but in the reduced form there are clear conformational changes in three of the carboxylate ligands and the bridging mu-oxo group and two water molecules are lost. In the reduced form of R2 the coordination number decreases from six to four for both ferrous ions, explaining their high reactivity towards dioxygen. The structure of the mutant Ser211--&gt; Ala, known to have impaired reduction kinetics, shows a large conformational change in one of the neighbouring helices although the iron coordination is very similar to the wild type protein. CONCLUSIONS. Carboxylate shifts are often important for carboxylate coordinated metal clusters; they allow the metals to achieve different coordination modes in redox reactions. In the case of reduced R2 these carboxylate shifts allow the formation of accessible reaction sites for dioxygen. The Ser211--&gt; Ala mutant displays a conformational change in the helix containing the mutation, explaining its altered reduction kinetics.
+
The line below this paragraph, {{ABSTRACT_PUBMED_8805591}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 8805591 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_8805591}}
==About this Structure==
==About this Structure==
Line 35: Line 39:
[[Category: Oxidoreductase]]
[[Category: Oxidoreductase]]
[[Category: Reductase]]
[[Category: Reductase]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:02:13 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 10:43:01 2008''

Revision as of 07:43, 28 July 2008

Image:1pfr.png

Template:STRUCTURE 1pfr

RIBONUCLEOSIDE-DIPHOSPHATE REDUCTASE 1 BETA CHAIN

Template:ABSTRACT PUBMED 8805591

About this Structure

1PFR is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

Crystal structure of reduced protein R2 of ribonucleotide reductase: the structural basis for oxygen activation at a dinuclear iron site., Logan DT, Su XD, Aberg A, Regnstrom K, Hajdu J, Eklund H, Nordlund P, Structure. 1996 Sep 15;4(9):1053-64. PMID:8805591

Page seeded by OCA on Mon Jul 28 10:43:01 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1pfr"
Personal tools