1z7r
From Proteopedia
(New page: 200px<br /><applet load="1z7r" size="450" color="white" frame="true" align="right" spinBox="true" caption="1z7r" /> '''Solution Structure of reduced glutaredoxin C...) |
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| - | [[Image:1z7r.gif|left|200px]]<br /><applet load="1z7r" size=" | + | [[Image:1z7r.gif|left|200px]]<br /><applet load="1z7r" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''Solution Structure of reduced glutaredoxin C1 from Populus tremula x tremuloides'''<br /> | '''Solution Structure of reduced glutaredoxin C1 from Populus tremula x tremuloides'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Glutaredoxins are glutathione-dependent enzymes that function to reduce | + | Glutaredoxins are glutathione-dependent enzymes that function to reduce disulfide bonds in vivo. Interestingly, a recent discovery indicates that some glutaredoxins can also exist in another form, an iron-sulfur protein [Lillig, C. H., et al. (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 8168-8173]. This provides a direct connection between glutaredoxins and iron-sulfur proteins, suggesting a possible new regulatory role of iron-sulfur clusters along with the new functional switch of glutaredoxins. Biochemical studies have indicated that poplar glutaredoxin C1 (Grx-C1) is also such a biform protein. The apo form (monomer) of Grx-C1 is a regular glutaredoxin, and the holo form (dimer) is an iron-sulfur protein with a bridging [2Fe-2S] cluster. Here, we report the structural characterizations of poplar Grx-C1 in both the apo and holo forms by NMR spectroscopy. The solution structure of the reduced apo Grx-C1, which is the first plant Grx structure, shows a typical Grx fold. When poplar Grx-C1 forms a dimer with an iron-sulfur cluster, each subunit of the holo form still retains the overall fold of the apo form. The bridging iron-sulfur cluster in holo Grx-C1 is coordinated near the active site. In addition to the iron-sulfur cluster linker, helix alpha3 of each subunit is probably involved in the direct contact between the two subunits. Moreover, two glutathione molecules are identified in the vicinity of the iron-sulfur cluster and very likely participate in cluster coordination. Taken together, we propose that the bridging [2Fe-2S] cluster is coordinated by the first cysteine at the glutaredoxin active site from each subunit of holo Grx-C1, along with two cysteines from two glutathione molecules. Our studies reveal that holo Grx-C1 has a novel structural and iron-sulfur cluster coordination pattern for an iron-sulfur protein. |
==About this Structure== | ==About this Structure== | ||
| - | 1Z7R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Populus_tremula_x_populus_tremuloides Populus tremula x populus tremuloides]. Full crystallographic information is available from [http:// | + | 1Z7R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Populus_tremula_x_populus_tremuloides Populus tremula x populus tremuloides]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z7R OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Feng, Y.]] | [[Category: Feng, Y.]] | ||
| - | [[Category: Jacquot, J | + | [[Category: Jacquot, J P.]] |
[[Category: Rouhier, N.]] | [[Category: Rouhier, N.]] | ||
[[Category: Xia, B.]] | [[Category: Xia, B.]] | ||
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[[Category: electron transport]] | [[Category: electron transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:12:52 2008'' |
Revision as of 14:12, 21 February 2008
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Solution Structure of reduced glutaredoxin C1 from Populus tremula x tremuloides
Overview
Glutaredoxins are glutathione-dependent enzymes that function to reduce disulfide bonds in vivo. Interestingly, a recent discovery indicates that some glutaredoxins can also exist in another form, an iron-sulfur protein [Lillig, C. H., et al. (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 8168-8173]. This provides a direct connection between glutaredoxins and iron-sulfur proteins, suggesting a possible new regulatory role of iron-sulfur clusters along with the new functional switch of glutaredoxins. Biochemical studies have indicated that poplar glutaredoxin C1 (Grx-C1) is also such a biform protein. The apo form (monomer) of Grx-C1 is a regular glutaredoxin, and the holo form (dimer) is an iron-sulfur protein with a bridging [2Fe-2S] cluster. Here, we report the structural characterizations of poplar Grx-C1 in both the apo and holo forms by NMR spectroscopy. The solution structure of the reduced apo Grx-C1, which is the first plant Grx structure, shows a typical Grx fold. When poplar Grx-C1 forms a dimer with an iron-sulfur cluster, each subunit of the holo form still retains the overall fold of the apo form. The bridging iron-sulfur cluster in holo Grx-C1 is coordinated near the active site. In addition to the iron-sulfur cluster linker, helix alpha3 of each subunit is probably involved in the direct contact between the two subunits. Moreover, two glutathione molecules are identified in the vicinity of the iron-sulfur cluster and very likely participate in cluster coordination. Taken together, we propose that the bridging [2Fe-2S] cluster is coordinated by the first cysteine at the glutaredoxin active site from each subunit of holo Grx-C1, along with two cysteines from two glutathione molecules. Our studies reveal that holo Grx-C1 has a novel structural and iron-sulfur cluster coordination pattern for an iron-sulfur protein.
About this Structure
1Z7R is a Single protein structure of sequence from Populus tremula x populus tremuloides. Full crystallographic information is available from OCA.
Reference
Structural insight into poplar glutaredoxin C1 with a bridging iron-sulfur cluster at the active site., Feng Y, Zhong N, Rouhier N, Hase T, Kusunoki M, Jacquot JP, Jin C, Xia B, Biochemistry. 2006 Jul 4;45(26):7998-8008. PMID:16800625
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