scholarly journals The AtNFS2 gene from Arabidopsis thaliana encodes a NifS-like plastidial cysteine desulphurase

2002 ◽  
Vol 366 (2) ◽  
pp. 557-564 ◽  
Author(s):  
Sébastien LÉON ◽  
Brigitte TOURAINE ◽  
Jean-François BRIAT ◽  
Stéphane LOBRÉAUX
Keyword(s):  
Arabidopsis Thaliana ◽  
Cluster Assembly ◽  
Synechocystis Pcc 6803 ◽  
Major Site ◽  
Reverse Transcription Pcr ◽  
Gfp Fusion Protein ◽  
Model Plant Arabidopsis Thaliana ◽  
Cluster Biosynthesis ◽  
Plant Arabidopsis Thaliana

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.

A multigene family of glycosyltransferases in a model plant, Arabidopsis thaliana

2002 ◽  
Vol 30 (2) ◽  
pp. 301-306 ◽  
Author(s):  
D. Bowles
Keyword(s):  
Arabidopsis Thaliana ◽  
Multigene Family ◽  
Sequence Similarity ◽  
Plant Cells ◽  
The Family ◽  
Model Plant Arabidopsis Thaliana ◽  
Group 1 ◽  
Plant Arabidopsis Thaliana

Glycosyltransferases transfer sugars from NDP-sugar donors to acceptors. The multigene family of transferases described in this paper typically transfer glucose from UDP-glucose to low-molecular-mass acceptors in the cytosol of plant cells. There are 107 sequences in the genome of Arabidopsis thaliana that contain a consensus, suggesting they belong to this Group 1 multigene family. The family has been analysed phylogenetically, and a functional genomics approach has been applied to explore the relatedness of sequence similarity to catalytic specificity and stereoselectivity. Enzymes belonging to this class of transferases glycosylate a vast array of acceptors, including natural products such as secondary metabolites and hormones, as well as xenobiotics absorbed by the plant, such as herbicides and pesticides. Conjugation to glucose potentially changes the activity of the acceptor molecule and invariably changes its location within the plant cell. Using the genomics approach described, a platform of knowledge has been constructed that will enable an understanding to be gained on the role of these enzymes in cellular homoeostasis, as well as their activity in biotransformations in vitro that require strict regioselectivity of glycosylation.

Glutathionylation of cytosolic glyceraldehyde-3-phosphate dehydrogenase from the model plant Arabidopsis thaliana is reversed by both glutaredoxins and thioredoxins in vitro

2012 ◽  
Vol 445 (3) ◽  
pp. 337-347 ◽  
Author(s):  
Mariette Bedhomme ◽  
Mattia Adamo ◽  
Christophe H. Marchand ◽  
Jérémy Couturier ◽  
Nicolas Rouhier ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Redox State ◽  
Irreversible Process ◽  
Reduced Glutathione ◽  
Eukaryotic Cells ◽  
Control Of Gene Expression ◽  
Mixed Disulfide ◽  
Model Plant Arabidopsis Thaliana ◽  
Plant Arabidopsis Thaliana

Plants contain both cytosolic and chloroplastic GAPDHs (glyceraldehyde-3-phosphate dehydrogenases). In Arabidopsis thaliana, cytosolic GAPDH is involved in the glycolytic pathway and is represented by two differentially expressed isoforms (GapC1 and GapC2) that are 98% identical in amino acid sequence. In the present study we show that GapC1 is a phosphorylating NAD-specific GAPDH with enzymatic activity strictly dependent on Cys149. Catalytic Cys149 is the only solvent-exposed cysteine of the protein and its thiol is relatively acidic (pKa=5.7). This property makes GapC1 sensitive to oxidation by H2O2, which appears to inhibit enzyme activity by converting the thiolate of Cys149 (–S−) into irreversible oxidized forms (–SO2− and –SO3−) via a labile sulfenate intermediate (–SO−). GSH (reduced glutathione) prevents this irreversible process by reacting with Cys149 sulfenates to give rise to a mixed disulfide (Cys149–SSG), as demonstrated by both MS and biotinylated GSH. Glutathionylated GapC1 can be fully reactivated either by cytosolic glutaredoxin, via a GSH-dependent monothiol mechanism, or, less efficiently, by cytosolic thioredoxins physiologically reduced by NADPH:thioredoxin reductase. The potential relevance of these findings is discussed in the light of the multiple functions of GAPDH in eukaryotic cells (e.g. glycolysis, control of gene expression and apoptosis) that appear to be influenced by the redox state of the catalytic Cys149.

scholarly journals The scope of flavin-dependent reactions and processes in the model plant Arabidopsis thaliana

2021 ◽  
Vol 189 ◽  
pp. 112822
Author(s):  
Reinmar Eggers ◽  
Alexandra Jammer ◽  
Shalinee Jha ◽  
Bianca Kerschbaumer ◽  
Majd Lahham ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Model Plant ◽  
Model Plant Arabidopsis Thaliana ◽  
Plant Arabidopsis Thaliana

scholarly journals The Flavoproteome of the Model Plant Arabidopsis thaliana

2020 ◽  
Vol 21 (15) ◽  
pp. 5371 ◽  
Author(s):  
Patrick Schall ◽  
Lucas Marutschke ◽  
Bernhard Grimm
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcriptional Control ◽  
Gene Families ◽  
Flavin Mononucleotide ◽  
Biotic And Abiotic Stress ◽  
Homologous Genes ◽  
Model Plant Arabidopsis Thaliana ◽  
Metabolic Activities ◽  
Flavin Binding ◽  
Plant Arabidopsis Thaliana

Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are essential cofactors for enzymes, which catalyze a broad spectrum of vital reactions. This paper intends to compile all potential FAD/FMN-binding proteins encoded by the genome of Arabidopsis thaliana. Several computational approaches were applied to group the entire flavoproteome according to (i) different catalytic reactions in enzyme classes, (ii) the localization in subcellular compartments, (iii) different protein families and subclasses, and (iv) their classification to structural properties. Subsequently, the physiological significance of several of the larger flavoprotein families was highlighted. It is conclusive that plants, such as Arabidopsis thaliana, use many flavoenzymes for plant-specific and pivotal metabolic activities during development and for signal transduction pathways in response to biotic and abiotic stress. Thereby, often two up to several homologous genes are found encoding proteins with high protein similarity. It is proposed that these gene families for flavoproteins reflect presumably their need for differential transcriptional control or the expression of similar proteins with modified flavin-binding properties or catalytic activities.

scholarly journals Iron–sulfur cluster biosynthesis

2008 ◽  
Vol 36 (6) ◽  
pp. 1112-1119 ◽  
Author(s):  
Sibali Bandyopadhyay ◽  
Kala Chandramouli ◽  
Michael K. Johnson
Keyword(s):  
Scaffold Proteins ◽  
Cluster Assembly ◽  
Cysteine Desulfurase ◽  
Iron Sulfur Cluster ◽  
Iron Sulfur ◽  
Eukaryotic Organisms ◽  
Almost All ◽  
Cluster Biosynthesis

Iron–sulfur (Fe–S) clusters are present in more than 200 different types of enzymes or proteins and constitute one of the most ancient, ubiquitous and structurally diverse classes of biological prosthetic groups. Hence the process of Fe–S cluster biosynthesis is essential to almost all forms of life and is remarkably conserved in prokaryotic and eukaryotic organisms. Three distinct types of Fe–S cluster assembly machinery have been established in bacteria, termed the NIF, ISC and SUF systems, and, in each case, the overall mechanism involves cysteine desulfurase-mediated assembly of transient clusters on scaffold proteins and subsequent transfer of pre-formed clusters to apo proteins. A molecular level understanding of the complex processes of Fe–S cluster assembly and transfer is now beginning to emerge from the combination of in vivo and in vitro approaches. The present review highlights recent developments in understanding the mechanism of Fe–S cluster assembly and transfer involving the ubiquitous U-type scaffold proteins and the potential roles of accessory proteins such as Nfu proteins and monothiol glutaredoxins in the assembly, storage or transfer of Fe–S clusters.

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