References of "Dusart, Jean"
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See detailThe induction of beta-lactamases in Eubacteria
Joris, Bernard ULg; Dusart, Jean

in Uversky, Vladimir N.; Frère, Jean-Marie (Eds.) Beta-lactamases (2012)

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See detailCrp of Streptomyces Coelicolor Is the Third Transcription Factor of the Large Crp-Fnr Superfamily Able to Bind Camp
Derouaux, Adeline ULg; Dehareng, Dominique ULg; Lecocq, Elke et al

in Biochemical and Biophysical Research Communications (2004), 325(3), 983-90

The chromosomal inactivation of the unique transcription factor of Streptomyces coelicolor that displays a cyclic-nucleotide-binding domain, Crp(Sco), led to a germination-defective phenotype similar to ... [more ▼]

The chromosomal inactivation of the unique transcription factor of Streptomyces coelicolor that displays a cyclic-nucleotide-binding domain, Crp(Sco), led to a germination-defective phenotype similar to the mutant of the adenylate cyclase gene (cya) unable to produce cAMP. By means of cAMP affinity chromatography we demonstrate the specific cAMP-binding ability of Crp(Sco), which definitely demonstrate that a Cya/cAMP/Crp system is used to trigger germination in S. coelicolor. However, electromobility shift assays with the purified Crp(Sco)-cAMP complex and the CRP-like cis-acting element of its own promoter failed. Moreover, we were unable to complement an Escherichia coli crp mutant in trans with Crp(Sco). The fact that Vfr from Pseudomonas aeruginosa and GlxR from Corynebacterium glutamicum could complement such an E. coli mutant suggests that the way Crp(Sco) interacts with DNA should mechanistically differ from its most similar members. This hypothesis was further supported by homology modelling of Crp(Sco) that confirmed an unusual organisation of the DNA-binding domain compared to the situation observed in Crp(Eco). [less ▲]

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See detailDeletion of a cyclic AMP receptor protein homologue diminishes germination and affects morphological development of Streptomyces coelicolor
Derouaux, Adeline ULg; Halici, S.; Nothaft, H. et al

in Journal of Bacteriology (2004), 186(6), 1893-1897

Open reading frame SCO3571 of Streptomyces coelicolor encodes a protein of the cyclic AMP (cAMP) receptor protein (CRP) superfamily of regulatory proteins. A mutant revealed a dramatic defect in ... [more ▼]

Open reading frame SCO3571 of Streptomyces coelicolor encodes a protein of the cyclic AMP (cAMP) receptor protein (CRP) superfamily of regulatory proteins. A mutant revealed a dramatic defect in germination, followed by growth delay and earlier sporulation. This phenotype correlates with those of an adenylate cyclase (cya) mutant that cannot synthesize cAMP. This finding suggests that S. coelicolor may use a Cya-cAMP-CRP system to trigger complex physiological processes such as morphogenesis. [less ▲]

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See detailRôle pléiotrope de la protéine CRP chez Streptomyces coelicolor
Derouaux, Adeline ULg; Titgemeyer, Fritz; Dusart, Jean et al

Conference (2004)

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See detailSite-directed mutagenesis of conserved inverted repeat sequences in the xylanase C promoter region from Streptomyces sp EC3
Giannotta, F.; Georis, J.; Rigali, Sébastien ULg et al

in Molecular Genetics & Genomics (2003), 270(4), 337-346

Streptomyces sp. EC3, a strain which was originally isolated from cattle manure compost, was shown to possess a strong xylanolytic activity. One of the genes responsible for this activity, xlnC, encodes a ... [more ▼]

Streptomyces sp. EC3, a strain which was originally isolated from cattle manure compost, was shown to possess a strong xylanolytic activity. One of the genes responsible for this activity, xlnC, encodes a secreted xylanase. In the native strain, as in the heterologous host S. lividans, expression of xlnC was detectable in the presence of xylan but not in the presence of glucose. Induction by xylan was shown to take place at the transcriptional level. The transcriptional start site of xlnC was mapped and likely -35 (5'-TTGACA-3') and -10 (5'-GAGAAC-3') motifs were identified. In order to localise putative conserved regulatory sequences, the promoter regions of xylanase-encoding genes from various Streptomyces species were aligned. This alignment revealed the existence of three sets of quite well conserved palindromic AT rich sequences called boxes 1, 2 and 3. Box 3 (5'-CGAAA N TTTCG-3') is the farthest away from the promoter region (150-200 bp). A shorter version of this palindrome (5'-GAAA NN TTTC-3') or (5'-CGAAA-3') constitutes box 1, which is located just upstream of the putative -35 promoter sequence. Box 2, located 5-7 bp upstream of box 1, comprises a shorter palindrome than box 3, with inverted polarity [5'-(G/C)TTTC (N) GAAA(G/C)-3']. The putative regulatory role of the conserved inverted repeats in boxes 2 and 3 in the promoter region of the xlnC gene from Streptomyces sp. EC3, was assessed. These boxes were modified by site-directed mutagenesis, and the mutant promoter regions, as well as the wild-type promoter region, were separately fused to a beta-lactamase reporter gene. Analysis of the expression patterns of these fusions in cultures grown in the presence of glucose, xylan or both carbon sources demonstrated that these motifs were cis -acting negative regulatory elements, each playing a specific role in the regulation of xlnC expression. Box 3 was shown to be critical for the establishment of repression of xlnC expression by glucose, whereas box 2 was shown to play an important role in the induction of xlnC expression by xylan. [less ▲]

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See detailStudy of the cap-like gene of Streptomyces coelicolor
Derouaux, Adeline ULg; Titgemeyrer, Fritz; Dusart, Jean et al

Poster (2003)

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See detailStudy of the crp-like gene of Streptomyces coelicolor
Derouaux, Adeline ULg; Titgemeyer, Fritz; Dusart, Jean et al

Poster (2003)

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See detailSubdivision of the helix-turn-helix GntR family of bacterial regulators in the FadR, HutC, MocR, and YtrA subfamilies
Rigali, Sébastien ULg; Derouaux, Adeline ULg; Giannotta, F. et al

in Journal of Biological Chemistry (2002), 277(15), 12507-12515

Haydon and Guest (Haydon, D. J, and Guest, J. R. (1991) FEMS Microbiol Lett. 63, 291-295) first described the helix-turn-helix GntR family of bacterial regulators. They presented them as transcription ... [more ▼]

Haydon and Guest (Haydon, D. J, and Guest, J. R. (1991) FEMS Microbiol Lett. 63, 291-295) first described the helix-turn-helix GntR family of bacterial regulators. They presented them as transcription factors sharing a similar N-terminal DNA-binding (D-b) domain, but they observed near-maximal divergence in the C-terminal effector-binding and oligomerization (E-b/O) domain. To elucidate this C-terminal heterogeneity, structural, phylogenetic, and functional analyses were performed on a family that now comprises about 270 members. Our comparative study first focused on the C-terminal E-b/O domains and next on DNA-binding domains and palindromic operator sequences, has classified the GntR members into four subfamilies that we called FadR, HutC, MocR, and YtrA. Among these subfamilies a degree of similarity of about 55% was observed throughout the entire sequence. Structure/function associations were highlighted although they were not absolutely stringent. The consensus sequences deduced for the DNA-binding domain were slightly different for each subfamily, suggesting that fusion between the D-b and E-b/O domains have occurred separately, with each subfamily having its own D-b domain ancestor. Moreover, the compilation of the known or predicted palindromic cis-acting elements has highlighted different operator sequences according to our subfamily subdivision. The observed C-terminal E-b/O domain heterogeneity was therefore reflected on the DNA-binding domain and on the cis-acting elements, suggesting the existence of a tight link between the three regions involved in the regulating process. [less ▲]

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See detailRôle du gène cap-like dans la répression catabolique chez Streptomyces
Derouaux, Adeline ULg; Giannotta, Fabrizio; Rigali, Sébastien ULg et al

Conference (2002)

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See detailCrystallographic analysis of family 11 endo-beta-1,4-xylanase Xyl1 from Streptomyces sp. S38.
Wouters, J.; Georis, J.; Engher, D. et al

in Acta Crystallographica Section D-Biological Crystallography (2001), 57(Pt 12), 1813-9

Family 11 endo-beta-1,4-xylanases degrade xylan, the main constituent of plant hemicelluloses, and have many potential uses in biotechnology. The structure of Xyl1, a family 11 endo-xylanase from ... [more ▼]

Family 11 endo-beta-1,4-xylanases degrade xylan, the main constituent of plant hemicelluloses, and have many potential uses in biotechnology. The structure of Xyl1, a family 11 endo-xylanase from Streptomyces sp. S38, has been solved. The protein crystallized from ammonium sulfate in the trigonal space group P321, with unit-cell parameters a = b = 71.49, c = 130.30 A, gamma = 120.0 degrees. The structure was solved at 2.0 A by X-ray crystallography using the molecular-replacement method and refined to a final R factor of 18.5% (R(free) = 26.9%). Xyl1 has the overall fold characteristic of family 11 xylanases, with two highly twisted beta-sheets defining a long cleft containing the two catalytic residues Glu87 and Glu177. [less ▲]

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See detailThe diversity, structure and regulation of beta-lactamases.
Philippon, A; Dusart, Jean; Joris, Bernard ULg et al

in Cellular and Molecular Life Sciences : CMLS (1998), 54(4), 341-6

beta-Lactamase production is responsible for the appearance of a large number of pathogenic bacterial strains exhibiting a high degree of resistance to beta-lactam antibiotics. A large number of enzymes ... [more ▼]

beta-Lactamase production is responsible for the appearance of a large number of pathogenic bacterial strains exhibiting a high degree of resistance to beta-lactam antibiotics. A large number of enzymes have been described with very diverse primary structures and catalytic profiles. Nevertheless, all known three-dimensional structures of active-site serine beta-lactamases exhibit a high degree of similarity with apparently equivalent chemical functionalities in the same strategic positions. These groups might not, however, play identical roles in the various classes of enzymes. Structural data have also been recently obtained for the zinc metallo-beta-lactamases, but the detailed catalytic mechanisms might also differ widely, depending on the enzyme studied. Similarly, the induction of the synthesis of beta-lactamases is now better understood, but many questions remain to be answered. [less ▲]

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See detailRésistance bactérienne aux beta-lactamines
Charlier, Paulette ULg; Coyette, Jacques ULg; Dehareng, Dominique ULg et al

in Medecine Sciences : M/S (1998), 14(5), 544-555

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See detailUse of an Automatic DNA Sequencer for S1 Mapping: Transcriptional Analysis of the Streptomyces Coelicolor A3(2) Dnak Operon
Brans, Alain ULg; Loriaux, Axelle; Thamm, Iris ULg et al

in FEMS Microbiology Letters (1997), 149(2), 189-94

The transcription start point of the dnaK operon of Streptomyces coelicolor A3(2) has been determined by S1 mapping, using the EMBL automated fluorescent DNA sequencer. The -35 and -10 hexamers correspond ... [more ▼]

The transcription start point of the dnaK operon of Streptomyces coelicolor A3(2) has been determined by S1 mapping, using the EMBL automated fluorescent DNA sequencer. The -35 and -10 hexamers correspond to a sigma 70-type promoter. This promoter responds to heat shock and involves an inverted repeat different from the CIRCE sequence characteristic of the Gram-positive heat-shock promoters. [less ▲]

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See detailThe two beta-lactamase genes of Streptomyces cacaoi, blaL and blaU, are under the control of the same regulatory system.
Magdalena, J; Gérard, Christine; Joris, Bernard ULg et al

in Molecular & General Genetics [=MGG] (1997), 255(2), 187-93

The production of beta-lactamase in Streptomyces cacaoi, which contains two beta-lactamase-encoding genes, blaL and blaU, is inducible by beta-lactam compounds. The two genes have been cloned ... [more ▼]

The production of beta-lactamase in Streptomyces cacaoi, which contains two beta-lactamase-encoding genes, blaL and blaU, is inducible by beta-lactam compounds. The two genes have been cloned independently in S. lividans TK24, a beta-lactamase-negative species. The blaU clone did not respond to the presence of beta-lactams, whereas the blaL clone appeared to be inducible in S. lividans. The latter clone contains two open reading frames, blaA and blaB, located just upstream of but transcribed divergently from blaL, which were shown to be required for the production as well as the induction of BlaL. The deduced BlaA protein belongs to the LysR family of transcription regulators. In order to examine the role of BlaA in regulation, we here report on over-expression of a GST-BlaA fusion protein in Escherichia coli and its use for antibody preparation. The GST-BlaA fusion protein was partially purified and bandshift assays showed that it bound the 197-bp blaL-blaA intergenic region. The BlaA DNA binding-site was further restricted to a 30-bp sequence containing a T-N11-A motif, a characteristic of LysR-type promoters. Another T-N11-A motif upstream of the blaU gene was also shown to bind BlaA. The affinities of these two T-N11-A motifs in BlaA binding were comparable. A plasmid bearing the blaU structural gene and the blaA-blaB regulatory region was constructed and shown to confer on an S. lividans host the capacity to produce inducible beta-lactamase. It can thus be concluded that the S. cacaoi blaL and blaU genes are controlled by the same regulatory system. [less ▲]

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See detailA Sequence-Specific DNA-Binding Protein Interacts with the Xlnc Upstream Region of Streptomyces Sp. Strain Ec3
Giannotta, F.; Georis, J.; Moreau, A. et al

in FEMS Microbiology Letters (1996), 142(1), 91-7

The alignment of the promoter region of several Streptomyces xylanases shows three conserved sequences which could be involved in gene regulation. By electromobility shift assays these specific sequences ... [more ▼]

The alignment of the promoter region of several Streptomyces xylanases shows three conserved sequences which could be involved in gene regulation. By electromobility shift assays these specific sequences, present only in Streptomyces xylanolytic strains, were identified as protein-binding sites. The sequence required for efficient recognition by the retarding protein appeared to be a 4-bp inverted repeat: 5'-CTTT-Nx-AAAG-3'. The DNA-protein affinity was influenced by the culture conditions. [less ▲]

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See detailCloning and Sequencing of the Dnak Locus in Streptomyces Coelicolor A3(2)
Brans, Alain ULg; Loriaux, Axelle; Joris, Bernard ULg et al

in DNA Sequence : The Journal of DNA Sequencing & Mapping (1996), 6(3), 179-84

The dnaK operon of Streptomyces coelicolor A3(2) was cloned by the DNA-probing method using synthetic oligonucleotides designed on the basis of two of the most conserved regions in 30 different DnaK ... [more ▼]

The dnaK operon of Streptomyces coelicolor A3(2) was cloned by the DNA-probing method using synthetic oligonucleotides designed on the basis of two of the most conserved regions in 30 different DnaK proteins (HSP70). The isolated insert-a BamHI 5.6-kb fragment-was sequenced and shown to contain three open-reading frames organized in an operon and coding for proteins analogous to DnaK, GrpE and DnaJ, successively. [less ▲]

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See detailRegulation Of The Beta-Lactamase Blal Of Streptomyces-Cacaoi - The Product Of The Blab Regulatory Gene Is An Internal Membrane-Bound Protein
Magdalena, J.; Joris, Bernard ULg; Vanbeeumen, J. et al

in Biochemical Journal (1995), 311

The beta-lactamase-encoding gene blaL, cloned from Streptomyces cacaoi in Streptomyces lividans, is inducible by beta-lactam compounds. This regulation has been shown to depend on the products of two open ... [more ▼]

The beta-lactamase-encoding gene blaL, cloned from Streptomyces cacaoi in Streptomyces lividans, is inducible by beta-lactam compounds. This regulation has been shown to depend on the products of two open reading frames, ORF1 (blaA) and ORF2 (blaB) [Lenzini, Magdalena, Fraipont, Joris, Matagne and Dusart (1992) Mol. Gen. Genet. 235, 41-48]. BlaA belongs to the LysR family of transcription activators, whereas BlaB shares some features with the penicillin-recognizing proteins. BlaB has now been overexpressed in Escherichia coli, purified and used for antibody preparation. Immunoblotting of cell-fractionated materials from S. cacaoi showed that BlaB is attached to the internal face of the cytoplasmic membrane. It could not be released by high salt concentrations or EDTA, but only by protease treatment. Under the assay conditions, BlaB did not act as a penicillin-binding protein, a beta-lactamase, a D-amino-peptidase or a target in a phosphorylation step. [less ▲]

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See detailErratum for : primary structure of the streptomyces R61 extracellular DD-peptidase. 1. Cloning into Streptomyces lividans and nucleotide sequence of the gene
Duez, Colette ULg; Piron-Fraipont, C.; Joris, Bernard ULg et al

in European Journal of Biochemistry (1994), 224(3), 1079

This is the correction of the fig. 5 of Primary structure of the Streptomyces R61 extracellular DD-peptidase. 1. Cloning into Streptomyces Zividuns and nucleotide sequence of the gene, by C. Duez, C ... [more ▼]

This is the correction of the fig. 5 of Primary structure of the Streptomyces R61 extracellular DD-peptidase. 1. Cloning into Streptomyces Zividuns and nucleotide sequence of the gene, by C. Duez, C. Piron-Fraipont, B. Joris, J. Dusart, M. S. Urdea, J. A. Martial, J.-M. Frère and J.-M. Ghuysen. European Journal of Biochemistry Volume 162, Issue 3, pages 509–518, February 1987 [less ▲]

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See detailImprovement of Gc-Rich Template Amplification by Inverse Pcr
Moreau, Alain; Duez, Colette ULg; Dusart, Jean

in BioTechniques (1994), 17(2), 232-4

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