Functional, structural, and spectroscopic characterization of a glutathione-ligated [2Fe-2S] cluster in poplar glutaredoxin C1.
When expressed in Escherichia coli, cytosolic poplar glutaredoxin C1 (CGYC active site) exists as a dimeric iron-sulfur-containing holoprotein or as a monomeric apoprotein in solution. Analytical and spectroscopic studies of wild-type protein and site-directed variants and structural characterization of the holoprotein by using x-ray crystallography indicate that the holoprotein contains a subunit-bridging [2Fe-2S] cluster that is ligated by the catalytic cysteines of two glutaredoxins and the cysteines of two glutathiones. Mutagenesis data on a variety of poplar glutaredoxins suggest that the incorporation of an iron-sulfur cluster could be a general feature of plant glutaredoxins possessing a glycine adjacent to the catalytic cysteine. In light of these results, the possible involvement of plant glutaredoxins in oxidative stress sensing or iron-sulfur biosynthesis is discussed with respect to their intracellular localization.
Rouhier
Nicolas
N
Unité Mixte de Recherche 1136, Institut National de la Recherche Agronomique, Institut Fédératif de Recherche 110, Genomics, Ecology, Nancy University, BP 239, 54506 Vandoeuvre-lès-Nancy Cedex, France. nrouhier@scbiol.uhp-nancy.fr
Unno
Hideaki
H
Bandyopadhyay
Sibali
S
Masip
Lluis
L
Kim
Sung-Kun
SK
Hirasawa
Masakazu
M
Gualberto
José Manuel
JM
Lattard
Virginie
V
Kusunoki
Masami
M
Knaff
David B
DB
Georgiou
George
G
Hase
Toshiharu
T
Johnson
Michael K
MK
Jacquot
Jean-Pierre
JP
D002460:Cell Line; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D004220:Disulfides / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D054477:Glutaredoxins; D005978:Glutathione / Q000737:chemistry* / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D032107:Populus / Q000378:metabolism*; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D013057:Spectrum Analysis; D013455:Sulfur / Q000378:metabolism; D014026:Nicotiana
D004220:Disulfides; D054477:Glutaredoxins; D007506:Iron-Sulfur Proteins; D008024:Ligands; D013455:Sulfur; D007501:Iron; D010088:Oxidoreductases; D005978:Glutathione