The AtNFS2 gene from Arabidopsis thaliana encodes a NifS-like plastidial cysteine desulphurase.
NifS-like proteins are cysteine desulphurases required for the mobilization of sulphur from cysteine. They are present in all organisms, where they are involved in iron-sulphur (Fe-S) cluster biosynthesis. In eukaryotes, these enzymes are present in mitochondria, which are the major site for Fe-S cluster assembly. The genome of the model plant Arabidopsis thaliana contains two putative NifS-like proteins. A cDNA corresponding to one of them was cloned by reverse-transcription PCR, and named AtNFS2. The corresponding transcript is expressed in many plant tissues. It encodes a protein highly related (75% similarity) to the slr0077-gene product from Synechocystis PCC 6803, and is predicted to be targeted to plastids. Indeed, a chimaeric AtNFS2-GFP fusion protein, containing one-third of AtNFS2 from its N-terminal end, was addressed to chloroplasts. Overproduction in Escherichia coli and purification of recombinant AtNFS2 protein enabled one to demonstrate that it bears a pyridoxal 5'-phosphate-dependent cysteine desulphurase activity in vitro, thus being the first NifS homologue characterized to date in plants. The putative physiological functions of this gene are discussed, including the attractive hypothesis of a possible role in Fe-S cluster assembly in plastids.
Léon
Sébastien
S
Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique (Unité Mixte de Recherche 5004), Université Montpellier-II, Institut National de la Recherche Agronomique et Ecole Nationale Supérieure d'Agronomie, France.
Touraine
Brigitte
B
Briat
Jean-François
JF
Lobréaux
Stéphane
S
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D013437:Carbon-Sulfur Lyases; D003001:Cloning, Molecular; D017931:DNA Primers; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008190:Lyases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D018514:Plant Structures / Q000201:enzymology; D018087:Plastids / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D017931:DNA Primers; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D008190:Lyases; D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase