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Cabos-Siguier B, Steunou AL, Joseph G, Alazard R, Ducoux-Petit M, Nieto L, Monsarrat B, Erard M, Clottes E. Expression and purification of human full-length N Oct-3, a transcription factor involved in melanoma growth. Protein Expr Purif 2009; 64:39-46. [DOI: 10.1016/j.pep.2008.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 10/09/2008] [Accepted: 10/20/2008] [Indexed: 11/28/2022]
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Alazard R, Mourey L, Ebel C, Konarev PV, Petoukhov MV, Svergun DI, Erard M. Fine-tuning of intrinsic N-Oct-3 POU domain allostery by regulatory DNA targets. Nucleic Acids Res 2007; 35:4420-32. [PMID: 17576670 PMCID: PMC1935007 DOI: 10.1093/nar/gkm453] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The 'POU' (acronym of Pit-1, Oct-1, Unc-86) family of transcription factors share a common DNA-binding domain of approximately 160 residues, comprising so-called 'POUs' and 'POUh' sub-domains connected by a flexible linker. The importance of POU proteins as developmental regulators and tumor-promoting agents is due to linker flexibility, which allows them to adapt to a considerable variety of DNA targets. However, because of this flexibility, it has not been possible to determine the Oct-1/Pit-1 linker structure in crystallographic POU/DNA complexes. We have previously shown that the neuronal POU protein N-Oct-3 linker contains a structured region. Here, we have used a combination of hydrodynamic methods, DNA footprinting experiments, molecular modeling and small angle X-ray scattering to (i) structurally interpret the N-Oct-3-binding site within the HLA DRalpha gene promoter and deduce from this a novel POU domain allosteric conformation and (ii) analyze the molecular mechanisms involved in conformational transitions. We conclude that there might exist a continuum running from free to 'pre-bound' N-Oct-3 POU conformations and that regulatory DNA regions likely select pre-existing conformers, in addition to molding the appropriate DBD structure. Finally, we suggest that a specific pair of glycine residues in the linker might act as a major conformational switch.
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Affiliation(s)
- Robert Alazard
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Christine Ebel
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Peter V. Konarev
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Maxim V. Petoukhov
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Dmitri I. Svergun
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Monique Erard
- Institut de Pharmacologie et de Biologie Structurale, 205 Route de Narbonne, 31077 Toulouse, Institut de Biologie Structurale, UMR 5075 CEA-CNRS-UJF, 41 rue Jules Horowitz, 38027 Grenoble, France and European Molecular Biology Laboratory, Hamburg Outstation, EMBL c/o DESY, D-22603 Hamburg, Germany and Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
- *To whom correspondence should be addressed. +33 (0) 562175496+33 (0) 562175994
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Alazard R, Blaud M, Elbaz S, Vossen C, Icre G, Joseph G, Nieto L, Erard M. Identification of the 'NORE' (N-Oct-3 responsive element), a novel structural motif and composite element. Nucleic Acids Res 2005; 33:1513-23. [PMID: 15767276 PMCID: PMC1065252 DOI: 10.1093/nar/gki284] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
N-Oct-3 is a neuronal transcription factor widely expressed in the developing mammalian central nervous system, and necessary to maintain neural cell differentiation. The key role of N-Oct-3 in the transcriptional regulation of a multiplicity of genes is primarily due to the structural plasticity of its so-called ‘POU’ (acronym of Pit, Oct, Unc) DNA-binding domain. We have recently reported about the unusual dual neuro-specific transcriptional regulation displayed by N-Oct-3 [Blaud,M., Vossen,C., Joseph,G., Alazard,R., Erard,M. and Nieto,L. (2004) J. Mol. Biol., 339, 1049–1058]. To elucidate the underlying molecular mechanisms, we have now made use of molecular modeling, DNA footprinting and electrophoretic mobility shift assay techniques. This combined approach has allowed us to uncover a novel mode of homodimerization adopted by the N-Oct-3 POU domain bound to the neuronal aromatic amino acids de-carboxylase and corticotropin-releasing hormone gene promoters and to demonstrate that this pattern is induced by a structural motif that we have termed ‘NORE’ (N-Oct-3 responsive element), comprising the 14 bp sequence element TNNRTAAATAATRN. In addition, we have been able to explain how the same structural motif can also induce the formation of a heterodimer in association with hepatocyte nuclear factor 3β(/Forkhead box a2). Finally, we discuss the possible role of the NORE motif in relation to neuroendocrine lung tumor formation, and in particular the development of small cell lung cancer.
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Affiliation(s)
| | | | | | | | | | | | | | - Monique Erard
- To whom correspondence should be addressed. Tel: +33 5 61 17 54 96; Fax: +33 5 61 17 59 94;
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Blaud M, Vossen C, Joseph G, Alazard R, Erard M, Nieto L. Characteristic Patterns of N Oct-3 Binding to a Set of Neuronal Promoters. J Mol Biol 2004; 339:1049-58. [PMID: 15178247 DOI: 10.1016/j.jmb.2004.04.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 04/02/2004] [Accepted: 04/08/2004] [Indexed: 10/26/2022]
Abstract
N Oct-3, a neurospecific POU protein, homodimerizes in a non-cooperative fashion on the neuronal aromatic l-amino acid decarboxylase gene promoter and generates heterodimers with HNF-3beta. Several other neuronal gene promoters, the corticotropin releasing hormone and the aldolase C gene promoters also contain overlapping binding sites for N Oct-3 and HNF-3beta. We have demonstrated that N Oct-3 presents a non-cooperative homodimerization on these two additional targets and can also give rise to heterodimers with HNF-3beta. Surprisingly, despite the high degree of conservation of the respective POU subunits, the ubiquitous POU protein Oct-1 can only form monomers even in the presence of either N Oct-3 or HNF-3beta on these DNA targets. Our data indicate that this difference is correlated with the specific ability of a portion of the N Oct-3 linker to fold as an alpha-helix, a property shared by class III POU proteins. These results suggest that this novel binding pattern permits the heterodimerization of N Oct-3 and HNF-3beta on the neuronal promoters, which could be a key issue in the development of the nervous system and possibly tumors of neural origin.
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Affiliation(s)
- Magali Blaud
- Laboratoire de Pharmacologie et de Biologie Structurale, CNRS UPR 9062, 205, route de Narbonne, 31077 Toulouse Cedex, France
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5
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Abstract
Efficient intermolecular transposition of bacterial insertion sequence IS911 involves the activities of two element-encoded proteins: the transposase, OrfAB, and a regulatory factor, OrfA. OrfA shares the majority of its amino acid sequence with the N-terminal part of OrfAB. This includes a putative helix-turn-helix and three of four heptads of a leucine zipper motif. OrfA strongly stimulates OrfAB-mediated intermolecular transposition both in vivo and in vitro. The present results support the notion that this is accomplished by direct interaction between these two proteins via the leucine zipper. We used both a genetic approach, based on gene fusions with phage lambda repressor, and a physical approach, involving co-immunoprecipitation, to show that OrfA not only undergoes oligomerisation but is capable of engaging with OrfAB to form heteromultimers, and that the leucine zipper is necessary for both types of interaction. Furthermore, mutation of the leucine zipper in OrfA inactivated its regulatory function. Previous observations demonstrated that the integrity of the leucine zipper motif was also important for OrfAB binding to the IS911 terminal inverted repeats. Here, we show, in gel shift experiments, using a derivative of OrfAB deleted for the C-terminal catalytic domain, OrfAB[1-149], that the protein is capable of pairing two inverted repeats to generate a species resembling a "synaptic complex". Preincubation of OrfAB[1-149] with OrfA dramatically reduced formation of this complex and favored formation of an alternative complex devoid of OrfA. Together these results suggest that OrfA exerts its regulatory effect by interacting transiently with OrfAB via the leucine zipper and modifying OrfAB binding to the inverted repeats.
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Affiliation(s)
- L Haren
- Laboratoire de Microbiologie et Génétique Moléculaire, CNRS Université Paul Sabatier, 118 Route de Narbonne, Toulouse, 31062, France
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Alazard R, Ebel C, Venien-Bryan V, Mourey L, Samama JP, Chandler M. Oligomeric structure of the repressor of the bacteriophage Mu early operon. Eur J Biochem 1998; 252:408-15. [PMID: 9546656 DOI: 10.1046/j.1432-1327.1998.2520408.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The regulation of the lytic and lysogenic development in the life cycle of bacteriophage Mu is regulated in part by its repressor, c, which binds to three operator sites, O1, O2 and O3, overlapping two divergent promoters. The oligomeric structure of this repressor protein was investigated by hydrodynamic and biochemical methods. Size-exclusion chromatography, analytical ultracentrifugation, dynamic light scattering, crosslinking and direct electron microscopy observations suggest that c exists primarily as a hexamer with a molecular mass of 120-140 kDa at low concentrations, i.e. in the 10-microM range. This molecule undergoes a self-assembly process leading to dodecamers and higher order species as the concentration is further increased in a manner depending on the nature of the solvent. Our results also suggest that these species have an elongated structure, and a possible arrangement of the subunits within the hexamer is proposed. The implication of this unusual quaternary structure for a repressor in its interaction with the operator sites O1 and O2 remains to be elucidated.
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Affiliation(s)
- R Alazard
- Laboratoire de Microbiologie et de Génétique Moléculaires, CNRS, Toulouse, France.
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Abstract
The repressor of bacteriophage Mu, c, binds to three operator sites, O1, O2, and O3, overlapping two divergent promoters, which regulate the lytic and lysogenic pathways. Its binding to this operator region generates several complexes, which were analyzed by DNase I protection experiments. We demonstrate that c first binds to two 11-base pair partially repeated sequences in O2 that could represent "core" binding sites for the repressor. This initial interaction serves as an organizer of a more complex nucleoprotein structure in which O2, O1, and O3 become successively occupied. The quaternary structure of the repressor was also investigated. Size exclusion chromatography and protein-protein crosslinking experiments with chemicals that possess linking arms of various lengths indicate that the repressor oligomerizes in solution. A model is proposed describing the successive interactions of c with the operator sites O2, O1, and O3 leading to the elaboration of a higher order structure in which the early lytic functions are repressed.
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Affiliation(s)
- P Rousseau
- Laboratoire de Microbiologie et Genetique Moleculaires, CNRS, Toulouse, France
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Betermier M, Rousseau P, Alazard R, Chandler M. Mutual stabilisation of bacteriophage Mu repressor and histone-like proteins in a nucleoprotein structure. J Mol Biol 1995; 249:332-41. [PMID: 7783197 DOI: 10.1006/jmbi.1995.0300] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Integration host factor (IHF) binds in a sequence-specific manner to the bacteriophage Mu early operator. It participates with bound Mu repressor, c, in building stable, large molecular mass nucleoprotein complexes in vitro and enhances repression of early transcription in vivo. We demonstrate that, when the specific IHF binding site with the operator is mutated, the appearance of large molecular mass complexes still depends on IHF and c, but the efficiency of their formation is reduced. Moreover, the IHF-like HU protein, which binds DNA in a non-sequence-specific way, can substitute for IHF and participate in complex formation. Since the complexes require both c and a host factor (IHF or HU), the results imply that these proteins stabilise each other within the nucleoprotein structures. These results suggest that IHF and HU are directed to the repressor-operator complexes, even in the absence of detectable sequence-specific binding. This could be a consequence of their preferential recognition of DNA containing a distortion such as that introduced by repressor binding to the operator. The histone-like proteins could then stabilise the nucleoprotein complexes simply by their capacity to maintain a bend in DNA rather than by specific protein-protein interactions with c. This model is supported by the observation that the unrelated eukaryotic HMG-1 protein, which exhibits a similar marked preference for structurally deformed DNA, is also able to participate in the formation of higher-order complexes with c and the operator DNA.
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Affiliation(s)
- M Betermier
- Laboratory of Molecular Genetics and Microbiology, C.N.R.S., Toulouse, France
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Bétermier M, Poquet I, Alazard R, Chandler M. Involvement of Escherichia coli FIS protein in maintenance of bacteriophage mu lysogeny by the repressor: control of early transcription and inhibition of transposition. J Bacteriol 1993; 175:3798-811. [PMID: 8389742 PMCID: PMC204797 DOI: 10.1128/jb.175.12.3798-3811.1993] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The Escherichia coli FIS (factor for inversion stimulation) protein has been implicated in assisting bacteriophage Mu repressor, c, in maintaining the lysogenic state under certain conditions. In a fis strain, a temperature-inducible Mucts62 prophage is induced at lower temperatures than in a wild-type host (M. Bétermier, V. Lefrère, C. Koch, R. Alazard, and M. Chandler, Mol. Microbiol. 3:459-468, 1989). Increasing the prophage copy number rendered Mucts62 less sensitive to this effect of the fis mutation, which thus seems to depend critically on the level of repressor activity. The present study also provides evidence that FIS affects the control of Mu gene expression and transposition. As judged by the use of lac transcriptional fusions, repression of early transcription was reduced three- to fourfold in a fis background, and this could be compensated by an increase in cts62 gene copy number. c was also shown to inhibit Mu transposition two- to fourfold less strongly in a fis host. These modulatory effects, however, could not be correlated to sequence-specific binding of FIS to the Mu genome, in particular to the strong site previously identified on the left end. We therefore speculate that a more general function of FIS is responsible for the observed modulation of Mu lysogeny.
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Affiliation(s)
- M Bétermier
- Molecular Genetics and Microbiology Laboratory, Centre National de la Recherche Scientifique UPR 9007, Toulouse, France
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10
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Abstract
Using gel retardation and DNase I protection techniques, we have demonstrated that the Escherichia coli integration host factor (IHF) stabilizes the interaction between Mu repressor and its cognate operator-binding sites in vitro. These results are discussed in terms of a model in which IHF may commit the phage to the lytic or lysogenic pathway depending on the occupancy of the operator sites by the repressor.
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Affiliation(s)
- R Alazard
- Centre de Recherches en Biochimie et Génétique Cellulaires, Toulouse, France
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Abstract
We have generated a series of 3' deletions of a cloned copy of the bacteriophage Mu transposase (A) gene. The corresponding truncated proteins, expressed under the control of the lambda PI promoter, were analysed in vivo for their capacity to complement a super-infecting MuAam phage, both for lytic growth and lysogeny, and for their effect on growth of wild-type Mu following infection or induction of a lysogen. Using crude cell extracts, we have also examined binding properties of these proteins to the ends of Mu. The results allow us to further define regions of the protein important in replicative transposition, establishment of lysogeny and DNA binding.
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Affiliation(s)
- M Bétermier
- Centre de Recherche de Biochimie et Génétique, Cellulaires du CNRS, Toulouse, France
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Bétermier M, Lefrère V, Koch C, Alazard R, Chandler M. The Escherichia coli protein, Fis: specific binding to the ends of phage Mu DNA and modulation of phage growth. Mol Microbiol 1989; 3:459-68. [PMID: 2548061 DOI: 10.1111/j.1365-2958.1989.tb00192.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We show, using gel retardation, that crude Escherichia coli cell extracts contain a protein which binds specifically to DNA fragments carrying either end of the phage Mu genome. We have identified this protein as Fis, a factor involved in several site-specific recombinational switches. Furthermore, we show that induction of a Mucts62 prophage in a fis lysogen occurs at a lower temperature than that of a wild-type strain, and that spontaneous induction of Mucts62 is increased in the fis mutant. DNasel footprinting using either crude extracts or purified Fis indicate that binding on the left end of Mu occurs at a site which overlaps a weak transposase binding site. Thus, Fis may modulate Mu growth by influencing the binding of transposase, or other proteins, to the transposase binding site(s), in a way similar to its influence on Xis binding in phage lambda.
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Affiliation(s)
- M Bétermier
- Centre de Recherche de Biochimie et Génétique Cellulaire de C.N.R.S., Toulouse, France
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Abstract
We devised a method for isolating mutations in the bacteriophage Mu A gene which encodes the phage transposase. Nine new conditional defective A mutations were isolated. These, as well as eight previously isolated mutations, were mapped with a set of defined deletions which divided the gene into 13 100- to 200-base-pair segments. Phages carrying these mutations were analyzed for their ability to lysogenize and to transpose in nonpermissive hosts. One Aam mutation, Aam7110, known to retain the capacity to support lysogenization of a sup0 host (M. M. Howe, K. J. O'Day, and D. W. Shultz, Virology 93:303-319, 1979) and to map 91 base pairs from the 3' end of the gene (R. M. Harshey and S. D. Cuneo, J. Genet. 65:159-174, 1987) was shown to be able to complement other A mutations for lysogenization, although it was incapable of catalyzing either the replication of Mu DNA or the massive conservative integration required for phage growth. Four Ats mutations which map at different positions in the gene were able to catalyze lysogenization but not phage growth at the nonpermissive temperature. Phages carrying mutations located at different positions in the Mu B gene (which encodes a product necessary for efficient integration and lytic replication) were all able to lysogenize at the same frequency. These results suggest that the ability of Mu to lysogenize is not strictly correlated with its ability to perform massive conservative and replicative transposition.
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Affiliation(s)
- A Toussaint
- Laboratoire de Génétique, Université Libre de Bruxelles, Rhode Saint Genèse, Belgium
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Betermier M, Alazard R, Ragueh F, Roulet E, Toussaint A, Chandler M. Phage Mu transposase: deletion of the carboxy-terminal end does not abolish DNA-binding activity. Mol Gen Genet 1987; 210:77-85. [PMID: 2828889 DOI: 10.1007/bf00337761] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We demonstrate that a specific site on the transposase protein, pA, of bacteriophage Mu is highly susceptible to proteolytic cleavage. Cleavage is observed in a minicell system on solubilisation with the non-ionic detergent Triton X-100 or following addition of a solubilised minicell preparation to pA synthesised in a cell-free coupled transcription/translation system. Cleavage occurs at the carboxy-terminal end of the protein and generates a truncated polypeptide of 64 kDa, pA*, which retains some of the DNA-binding properties of pA. These results suggest that pA may be divided into functional domains for DNA binding and for interaction with the proteins involved in phage replication.
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Griffin JH, DiBello C, Alazard R, Nicolas P, Cohen P. Carbon-13 nuclear magnetic resonance studies of the binding of selectively 13C-enriched oxytocins to the neurophypophyseal protein, bovine neurophysin II. Biochemistry 1977; 16:4194-8. [PMID: 561612 DOI: 10.1021/bi00638a010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Complex formation between bovine neurophysin II and oxytocin molecules containing 85% 13C enrichment in specific amino acid residues was studied using 13C nuclear magnetic resonance spectroscopy. Chemical shift and relaxation time values of the analogue [13C-Leu3]oxytocin, [13C-Gly9]oxytocin, and the doubly labeled [13C-Ile3 Gly9]oxytocin were obtained for the hormones in the absence and presence of neurophysin. The results showed that certain 13C nuclear magnetic resonance parameters of residue 3 but not of residue 9 of oxytocin are altered upon binding to neurophysin. These observations suggest that residue 3 but not residue 9 is involved in the protein-hormone interaction and they demonstrate the general applicability of selective 13C enrichment for the study of peptide-protein interactions.
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Wolff J, Alazard R, Camier M, Griffin JH, Cohen P. Interactions of bovine neurophysins with neurohypophyseal hormones. On the role of tyrosine-49. J Biol Chem 1975; 250:5215-20. [PMID: 1150656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Reaction of tetranitromethane with the lone tyrosine residue of bovine neurophysin I and II, tyrosine-49, gave nitro derivatives of these proteins which were obtained in a highly purified form by preparative electrophoresis. Equilibrium dialysis experiments indicated clearly that oxytocin binding remained essentially unaffected by the chemical modification of tyrosine-49. However, in the case of (8-lysine)vasopressin, the nitrated protein was found to bind only 1 hormone molecule in contrast to the 2 vasopressin molecules bound by the native protein. Ultraviolet absorption difference spectroscopy measurements between 250 nm and 300 nm indicated that upon binding of (2-phenylalanine, 8-lysine)vasopressin, tyrosine-49 of native neurophysin undergoes a change of microenvironment from less to more polar surroundings. Studies of the nitrotyrosyl-49 chromophore of neurophysin by ab sorption spectroscopy in the absence and presence of oxytocin or (8-lysine)vasopressin confirmed this finding. Since dimethylsulfoxide solvent perturbation studies suggested that in the Cys(Me)-Phe-Ile-NH2-neurophysin I complex, tyrosine-49 is more exposed to solvent than in neurophysin I alone, it is concluded that this residue is unmasked by conformational changes upon complex formation.
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Griffin JH, Alazard R, Dibello C, Sala E, Mermet-Bouvier R, Cohen P. Carbon-13 nuclear magnetic resonance studies on (85 per cent 13C-enriched Gly 9) oxytocin. FEBS Lett 1975; 50:168-71. [PMID: 1112410 DOI: 10.1016/0014-5793(75)80481-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Alazard R, Cohen P, Cohen JS, Griffin JH. Interactions of bovine neurophysin II with oxytocin and (8-lysine) vasopressin. High resolution proton nuclear magnetic resonance spectroscopy studies. J Biol Chem 1974; 249:6895-900. [PMID: 4423570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Griffin JH, Alazard R, Cohen P. Complex formation between bovine neurophysin-I and oxytocin, vasopressin, and tripeptide analogs of their NH2-terminal region. Absorbance and circular dichroism difference spectroscopic studies. J Biol Chem 1973; 248:7975-8. [PMID: 4796247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Alazard R, Béchet JJ, Dupaix A, Yon J. Inactivation of alpha-chymotrypsin by a bifunctional reagent, 2-bromomethyl-3, I-benzoxazin-4-one. Biochim Biophys Acta 1973; 309:379-96. [PMID: 4731968 DOI: 10.1016/0005-2744(73)90037-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Camier M, Alazard R, Cohen P. Hormonal interactions at the molecular level. A study of oxytocin and vasopressin binding to bovine neurophysins. Eur J Biochem 1973; 32:207-14. [PMID: 4734532 DOI: 10.1111/j.1432-1033.1973.tb02598.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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