CGFS-type monothiol glutaredoxins from the cyanobacterium Synechocystis PCC6803 and other evolutionary distant model organisms possess a glutathione-ligated [2Fe-2S] cluster.
When produced in Escherichia coli, the CGFS-type monothiol Grxs from this organism (EcGrx4p) and the model cyanobacterium Synechocystis (SyGrx3p) exist as a dimeric iron-sulfur containing holoprotein or as a monomeric apoprotein in solution. Spectroscopic and site-directed mutagenesis analyses show that the SyGrx3 holoprotein contains a subunit-bridging [2Fe-2S] cluster that is ligated by the catalytic cysteine located in the CGFS motif of each monomer and the cysteines of two molecules of glutathione. The biochemical characterization of several monothiol Grxs from the cyanobacteria Gloeobacter violaceus (GvGrx3p) and Thermosynechococcus elongatus (TeGrx3p), the yeast Saccharomyces cerevisiae (ScGrx3p, ScGrx4p, and ScGrx5p), the plant Arabidopsis thaliana (AtGrx5p), and human (HsGrx5p) indicate that the incorporation of a GSH-ligated [2Fe-2S] center is a common feature of prokaryotic and eukaryotic CGFS-active site monothiol Grxs. In light of these results, the involvement of these enzymes in the sensing of iron and/or the biogenesis and transfer of Fe-S cluster is discussed.
Picciocchi
Antoine
A
CEA, iBiTec-S, SBIGeM, LBI, Bat 142 CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France.
Saguez
Cyril
C
Boussac
Alain
A
Cassier-Chauvat
Corinne
C
Chauvat
Franck
F
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics / Q000378:metabolism; D017124:Conserved Sequence; D003545:Cysteine / Q000378:metabolism; D019143:Evolution, Molecular; D054477:Glutaredoxins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005978:Glutathione / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013438:Sulfhydryl Compounds; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics
D000596:Amino Acids; D054477:Glutaredoxins; D007506:Iron-Sulfur Proteins; D008024:Ligands; D013438:Sulfhydryl Compounds; D005978:Glutathione; D003545:Cysteine