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See detailDie Zikadenmetapher in Ingeborg Bachmanns Die Zikaden: Lebensflucht und Lebensmut
Vanhaegendoren, Koen ULiege

in Seminar: a Journal of Germanic Studies (2006), 42(2), 135-154

Detailed reference viewed: 87 (1 ULiège)
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See detailZilberberg – Hjelmslev : aller – retour
Badir, Sémir ULiege

in Badir, Sémir; Ablali, Driss (Eds.) Analytiques du sensible. Pour Claude Zilberberg (2009)

Detailed reference viewed: 23 (0 ULiège)
See detailZinc and Iron interplay in Arabidopsis relatives
Hanikenne, Marc ULiege

Conference (2016, May 24)

Detailed reference viewed: 13 (1 ULiège)
See detailZinc and Iron interplay in Arabidopsis relatives
Hanikenne, Marc ULiege

Scientific conference (2016, March 25)

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See detailZinc Beta-lactamase superfamily
Bebrone, Carine ULiege

in Kretsinger, Robert; Uversky, Vladimir; Permyakov, Eugene (Eds.) Encyclopedia of Metalloproteins (2013)

The metallo-beta-lactamase superfamily was first defined in 1997 on the basis of a sequence alignment. The members of this superfamily are characterized by the presence of a common alpha-beta-beta-alpha ... [more ▼]

The metallo-beta-lactamase superfamily was first defined in 1997 on the basis of a sequence alignment. The members of this superfamily are characterized by the presence of a common alpha-beta-beta-alpha fold and share five conserved motifs: Asp84, His116-Xaa-His118-Xaa-Asp120-His121, His196, Asp221 and His263, which are (with the exception of Asp84) involved in the binding of two metal ions. This superfamily contains now more than 23,900 members divided into 17 biological groups. Besides metallo-beta-lactamases which cleave the amide bond of the β-lactam ring of penicillins, cephalosporins or carbapenems (thus inactivating the antibiotic), the metallo-beta-lactamase superfamily includes enzymes which hydrolyze thiol-ester, phosphodiester and sulfuric ester bonds as well as oxydoreductases. [less ▲]

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See detailThe Zinc Center Influences the Redox and Thermodynamic Properties of Escherichia coli Thioredoxin 2
El Hajjaji, Hayat; Dumoulin, Mireille ULiege; Matagne, André ULiege et al

in Journal of Molecular Biology (2009), 386(1), 60-71

Thioredoxins are small, ubiquitous redox enzymes that reduce protein disulfide bonds by using a pair of cysteine residues present in a strictly conserved WCGPC catalytic motif. The Escherichia coli ... [more ▼]

Thioredoxins are small, ubiquitous redox enzymes that reduce protein disulfide bonds by using a pair of cysteine residues present in a strictly conserved WCGPC catalytic motif. The Escherichia coli cytoplasm contains two thioredoxins, Trx1 and Trx2. Trx2 is special because it is induced under oxidative stress conditions and it has an additional N-terminal zinc-binding domain. We have determined the redox potential of Trx2, the pKa of the active site nucleophilic cysteine, as well as the stability of the oxidized and reduced form of the protein. Trx2 is more oxidizing than Trx1 (–221 mV versus –284 mV, respectively), which is in good agreement with the decreased value of the pKa of the nucleophilic cysteine (5.1 versus 7.1, respectively). The difference in stability between the oxidized and reduced forms of an oxidoreductase is the driving force to reduce substrate proteins. This difference is smaller for Trx2 (ΔΔG°H2O = 9 kJ/mol and ΔTm = 7. 4 °C) than for Trx1 (ΔΔG°H2O = 15 kJ/mol and ΔTm = 13 °C). Altogether, our data indicate that Trx2 is a significantly less reducing enzyme than Trx1, which suggests that Trx2 has a distinctive function. We disrupted the zinc center by mutating the four Zn2+-binding cysteines to serine. This mutant has a more reducing redox potential (–254 mV) and the pKa of its nucleophilic cysteine shifts from 5.1 to 7.1. The removal of Zn2+ also decreases the overall stability of the reduced and oxidized forms by 3.2 kJ/mol and 5.8 kJ/mol, respectively. In conclusion, our data show that the Zn2+-center of Trx2 fine-tunes the properties of this unique thioredoxin. [less ▲]

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See detailZinc complexes with 1,2,4-triazole functionalized amino acid derivatives: Synthesis, structure and b-lactamase assay
Naik, Anil; Beck, Joséphine; Dîrtu, Marinela et al

in Inorganica Chimica Acta (2011), 368

Coordinating abilities of 4R-1,2,4-triazole derivatives (R = glycine ethyl ester (L1), glycine (L2), diethylamino malonate (L3), methionine (L4) and diethyl aminomethylphosphonate (L5)) towards ZnII ions ... [more ▼]

Coordinating abilities of 4R-1,2,4-triazole derivatives (R = glycine ethyl ester (L1), glycine (L2), diethylamino malonate (L3), methionine (L4) and diethyl aminomethylphosphonate (L5)) towards ZnII ions have been studied in solution, in solid state and versus three zinc-b-lactamases. The crystal structure of [Zn3(L4)6(H2O)6] (6) is described; it is the first crystal structure involving a 1,2,4-triazole functionalized methionine. It forms a trinuclear complex with central zinc octahedrally coordinated by only L4, whereas terminal zinc ions coordination sphere is completed by three water molecules. L4 exhibits a dual functionality of a bridging bidentate ligand as well as an anion. A dense hydrogen bonding network connects these trinuclear entity into a 3D supramolecular network. The ZnII ions in 6 are held at equidistance (3.848 Å) which coincidently matches with the corresponding Zn Zn distance in the binuclear zinc enzyme from Bacillus cereus (3.848 and 4.365 Å). Among L1–L5 screened for b-lactamase assay, L4 shows modest inhibition for BcII enzyme. [less ▲]

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See detailZinc D-Ala-D-Ala carboxypeptidase
Ghuysen, Jean-Marie ULiege

in CLAN MD (n.d.)

Detailed reference viewed: 8 (3 ULiège)
See detailZinc D-Ala-D-Ala carboxypeptidase (Streptomyces)
Ghuysen, Jean-Marie ULiege

in Barret, Alan J.; Rawling, Neil D.; Woessner, J. Fred (Eds.) Handbook of Proteolytic Enzymes. vol 2 Cysteine, Serine and Threonine Peptidases (2004)

This endopeptidase was identified as a zinc enzyme and has been given the name zinc-D-Ala-D-Ala carboxypeptidase. It contains 1 mol of zinc per 18,000 Da protein mol., the apoprotein binds Zn2+ with Ka of ... [more ▼]

This endopeptidase was identified as a zinc enzyme and has been given the name zinc-D-Ala-D-Ala carboxypeptidase. It contains 1 mol of zinc per 18,000 Da protein mol., the apoprotein binds Zn2+ with Ka of 2 × 1014M-1 and the Zn2+ cofactor is required for activity. The activity and specificity, structural chem., and prepn. of zinc-D-Ala-D-Ala carboxypeptidase are discussed. [less ▲]

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See detailZinc excess and the cell cycle control in Arabidopsis sp.
Thiébaut, Noémie ULiege; Zarattini, Marco; Verbruggen, Nathalie et al

Poster (2019, February 07)

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See detailA "zinc finger-like" domain in the 54KDA protein of several pestiviruses
De Moerlooze, L.; Renard, A.; Lecomte, C. et al

in Archives of Virology. Supplementum (1991), 3

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See detailZinc hyperaccumulation: a model to examine metal homeostasis in plants
Hanikenne, Marc ULiege

Scientific conference (2012, September 28)

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See detailZinc hyperaccumulation: a model to examine metal homeostasis in plants
Hanikenne, Marc ULiege

Scientific conference (2012, December 05)

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See detailZinc hyperaccumulation: a model to examine metal homeostasis in plants
Hanikenne, Marc ULiege; Nouet, Cécile ULiege; Charlier, Jean-Benoit et al

Conference (2012, September 20)

The plant Arabidopsis halleri exhibits naturally selected metal hypertolerance and extraordinarily high levels of leaf metal accumulation. Metal hyperaccumulator species attract interest as they represent ... [more ▼]

The plant Arabidopsis halleri exhibits naturally selected metal hypertolerance and extraordinarily high levels of leaf metal accumulation. Metal hyperaccumulator species attract interest as they represent an extreme end of natural variation of the metal homeostasis network. This might be useful to reveal the global functioning of metal homeostasis networks and uncover key nodes whose alterations can drastically modify metal accumulation and tolerance. In addition, metal hyperaccumulation is a compelling model to study adaptation. In the last few years, major progress has been achieved in our understanding of the mechanisms underlying metal hyperaccumulation in A. halleri. High rates of metal uptake by roots, root-to-shoot translocation and efficient shoot vacuolar sequestration play central roles in determining hyperaccumulation and hypertolerance. Enhanced functions of several metal transporter-encoding genes result from gene copy number amplification and/or (cis)-regulatory changes. We will describe the function of several transporters in zinc and cadmium hyperaccumulation and hypertolerance, and in the adjustment of nutrient homeostasis in A. halleri. Recent work aiming to determine if selection acted during the evolutionary history of A. halleri on a loci required for metal tolerance and accumulation will be presented. [less ▲]

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See detailZinc triggers a complex transcriptional and post-transcriptional regulation of the metal homeostasis gene FRD3 in Arabidopsis relatives
Charlier, Jean_Benoit; Polese, Catherine; Nouet, Cécile ULiege et al

in Journal of Experimental Botany (2015), 66

In Arabidopsis thaliana, FRD3 (Ferric Chelate Reductase Defective 3) plays a central role in metal homeostasis. FRD3 is among a set of metal homeostasis genes that are constitutively highly expressed in ... [more ▼]

In Arabidopsis thaliana, FRD3 (Ferric Chelate Reductase Defective 3) plays a central role in metal homeostasis. FRD3 is among a set of metal homeostasis genes that are constitutively highly expressed in roots and shoots of Arabidopsis halleri, a zinc hyperaccumulating and hypertolerant species. Here, we examined the regulation of FRD3 by zinc in both species to shed light on the evolutionary processes underlying the evolution of hyperaccumulation in A. halleri. We combined gene expression studies with the use of GUS and GFP reporter constructs to compare the expression profile, transcriptional and post-transcriptional regulation of FRD3 in both species. The AtFRD3 and AhFRD3 genes display a conserved expression profile. In A. thaliana, alternative transcription initiation sites from two promoters determine transcript variants which are differentially regulated by zinc supply in roots and shoots to favour the most highly translated variant under zinc excess conditions. In A. halleri, a single transcript variant with higher transcript stability and enhanced translation has been maintained. The FRD3 gene thus undergoes complex transcriptional and post-transcriptional regulation in Arabidopsis relatives. Our study reveals that a diverse set of mechanisms underlie increased gene dosage in the A. halleri lineage and illustrates how an environmental challenge can alter gene regulation. [less ▲]

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See detailZinc, iron and manganese interaction within the frd3 Arabidopsis mutant
Scheepers, Maxime ULiege; Spielmann, Julien ULiege; Goormaghtigh, Erik et al

Poster (2016, November 16)

Zinc and iron are two essential micronutrients for plants. The homeostasis networks of the two metals are intertwined. Arabidopsis halleri is a zinc- and cadmium-tolerant and zinc-hyperaccumulating ... [more ▼]

Zinc and iron are two essential micronutrients for plants. The homeostasis networks of the two metals are intertwined. Arabidopsis halleri is a zinc- and cadmium-tolerant and zinc-hyperaccumulating species, which also present adaptation of its iron homeostasis(1,4). Transcriptomic studies identified genes which are constitu-tively over-expressed in Arabidopsis halleri compared to Arabidopsis thaliana and which may have a role in metal tolerance or accumulation(2-4). Among them, a candidate gene encodes the FRD3 (FERRIC REDUCTASE DEFECTIVE 3) protein, a member of the MATE family of membrane transporters. FRD3 is a citrate transporter involved in iron homeostasis(5-7) and plays a role in zinc tolerance in A. thaliana(8). The FRD3 gene displays a complex regulation. In A. thaliana, alternative transcript initiation for FRD3 determines two transcripts, which dif-fer in their 5'UTRs and have differential translation efficiency. The two transcripts are selectively regulated under stress conditions: iron and zinc depletion, zinc excess or cadmium presence(9). In A. halleri, a single highly ex-pressed FRD3 transcript with high translation efficiency is present(9). [less ▲]

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See detailZinc, manganese and iron interaction within the frd3 Arabidopsis mutant
Scheepers, Maxime ULiege; Spielmann, Julien ULiege; Goormaghtigh, Erik et al

Poster (2017, February 01)

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See detailZinc-dependent global transcriptional control, transcriptional deregulation, and higher gene copy number for genes in metal homeostasis of the hyperaccumulator Arabidopsis halleri
Talke, Ina N.; Hanikenne, Marc ULiege; Krämer, Ute

in Plant Physiology (2006), 142(1), 148-167

The metal hyperaccumulator Arabidopsis halleri exhibits naturally selected zinc (Zn) and cadmium (Cd) hypertolerance and accumulates extraordinarily high Zn concentrations in its leaves. With these ... [more ▼]

The metal hyperaccumulator Arabidopsis halleri exhibits naturally selected zinc (Zn) and cadmium (Cd) hypertolerance and accumulates extraordinarily high Zn concentrations in its leaves. With these extreme physiological traits, A. halleri phylogenetically belongs to the sister clade of Arabidopsis thaliana. Using a combination of genome-wide cross species microarray analysis and real-time reverse transcription-PCR, a set of candidate genes is identified for Zn hyperaccumulation, Zn and Cd hypertolerance, and the adjustment of micronutrient homeostasis in A. halleri. Eighteen putative metal homeostasis genes are newly identified to be more highly expressed in A. halleri than in A. thaliana, and 11 previously identified candidate genes are confirmed. The encoded proteins include HMA4, known to contribute to root-shoot transport of Zn in A. thaliana. Expression of either AtHMA4 or AhHMA4 confers cellular Zn and Cd tolerance to yeast (Saccharomyces cerevisiae). Among further newly implicated proteins are IRT3 and ZIP10, which have been proposed to contribute to cytoplasmic Zn influx, and FRD3 required for iron partitioning in A. thaliana. In A. halleri, the presence of more than a single genomic copy is a hallmark of several highly expressed candidate genes with possible roles in metal hyperaccumulation and metal hypertolerance. Both A. halleri and A. thaliana exert tight regulatory control over Zn homeostasis at the transcript level. Zn hyperaccumulation in A. halleri involves enhanced partitioning of Zn from roots into shoots. The transcriptional regulation of marker genes suggests that in the steady state, A. halleri roots, but not the shoots, act as physiologically Zn deficient under conditions of moderate Zn supply. [less ▲]

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See detail'Een zingen in aanvankelijkheid'. Muziek als inspiratiebron bij Ida Gerhardt
Steyaert, Kris ULiege

in Spiegel der Letteren (2012), 54(2), 271-273

Detailed reference viewed: 57 (8 ULiège)