1h0o: Difference between revisions
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[[Image:1h0o.gif|left|200px]]<br /> | [[Image:1h0o.gif|left|200px]]<br /><applet load="1h0o" size="450" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1h0o" size="450" color="white" frame="true" align="right" spinBox="true" | |||
caption="1h0o, resolution 2.2Å" /> | caption="1h0o, resolution 2.2Å" /> | ||
'''COBALT SUBSTITUTION OF MOUSE R2 RIBONUCLEOTIDE REDUCTASE TO MODEL THE REACTIVE DIFERROUS STATE'''<br /> | '''COBALT SUBSTITUTION OF MOUSE R2 RIBONUCLEOTIDE REDUCTASE TO MODEL THE REACTIVE DIFERROUS STATE'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
1H0O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with CO as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] | 1H0O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with CO as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Known structural/functional Site: <scene name='pdbsite=CO1:Co Binding Site For Chain A'>CO1</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1H0O OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: ribonucleotide reductase]] | [[Category: ribonucleotide reductase]] | ||
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Revision as of 16:40, 18 December 2007
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COBALT SUBSTITUTION OF MOUSE R2 RIBONUCLEOTIDE REDUCTASE TO MODEL THE REACTIVE DIFERROUS STATE
OverviewOverview
The R2 dimer of mouse ribonucleotide reductase contains a dinuclear, iron-oxygen cluster and tyrosyl radical/subunit. The dinuclear diferrous, form reacts with dioxygen to generate the tyrosyl radical essential for, the catalytic reaction that occurs at the R1 dimer. It is important to, understand how the reactivity toward oxygen is related to the crystal, structure of the dinuclear cluster. For the mouse R2 protein, no structure, has been available with a fully occupied dinuclear metal ion site. A, cobalt substitution of mouse R2 was performed to produce a good model for, the very air-sensitive diferrous form of the enzyme. X-band EPR and light, absorption studies (epsilon(550 nm) = 100 mm(-1) cm(-1)/Co(II)) revealed a, strong cooperative binding of cobalt to the dinuclear site. In, perpendicular mode EPR, the axial signal from mouse R2 incubated with, Co(II) showed a typical S = 3/2 Co(II) signal, and its low intensity, indicated that the majority of the Co(II) bound to R2 is magnetically, coupled. In parallel mode EPR, a typical integer spin signal (M(s) = +/-3), with g approximately 12 is observed at 3.6 K and 10 K, showing that the, two Co(II) ions (S = 3/2) in the dinuclear site are ferromagnetically, coupled. We have solved the 2.4 A crystal structure of the, Co(II)-substituted R2 with a fully occupied dinuclear cluster. The, bridging Co(II) carboxylate ligand Glu-267 adopts an altered orientation, compared with its counterpart Glu-238 in Escherichia coli R2. This might, be important for proper O(2) activation of the more exposed native, diferrous site in mouse R2 compared with E. coli R2.
About this StructureAbout this Structure
1H0O is a Single protein structure of sequence from Mus musculus with CO as ligand. Active as Ribonucleoside-diphosphate reductase, with EC number 1.17.4.1 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Cobalt substitution of mouse R2 ribonucleotide reductase as a model for the reactive diferrous state Spectroscopic and structural evidence for a ferromagnetically coupled dinuclear cobalt cluster., Strand KR, Karlsen S, Andersson KK, J Biol Chem. 2002 Sep 13;277(37):34229-38. Epub 2002 Jun 26. PMID:12087093
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