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Your search keyword '"Auzat, Isabelle"' showing total 3 results
Start Over Author "Auzat, Isabelle" Topic electron microscopy
3 results on '"Auzat, Isabelle"'

2. Bacteriophage SPP1 tail tube protein self-assembles into β-structure-rich tubes

Author

Langlois, Chantal, Ramboarina, Stéphanie, Cukkemane, Abhishek, Auzat, Isabelle, Chagot, Benjamin, Gilquin, Bernard, Ignatiou, Athanasios, Petitpas, Isabelle, Kasotakis, Emmanouil, Paternostre, Maïté, White, Helen E., Orlova, Elena V., Baldus, Marc, Tavares, Paulo, Zinn-Justin, Sophie, Sub NMR Spectroscopy, NMR Spectroscopy, Institut de Biologie et de Technologies de Saclay (IBITECS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Biologie Structurale et Radiobiologie (LBSR), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands, Laboratoire de Virologie Moléculaire et Structurale, Centre National de la Recherche Scientifique (CNRS), Institute of Structural & Molecular Biology, Birkbeck College, University College of London [London] (UCL), Interactions et mécanismes d’assemblage des protéines et des peptides (IMAPP), Département Biochimie, Biophysique et Biologie Structurale (B3S), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie et de Technologies de Saclay ( IBITECS ), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire de Biologie Structurale et Radiobiologie ( LBSR ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Centre National de la Recherche Scientifique ( CNRS ), University College of London [London] ( UCL ), Interactions et mécanismes d’assemblage des protéines et des peptides ( IMAPP ), Département Biochimie, Biophysique et Biologie Structurale ( B3S ), Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Institut de Biologie Intégrative de la Cellule ( I2BC ), Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ) -Université Paris-Sud - Paris 11 ( UP11 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Centre National de la Recherche Scientifique ( CNRS ), Sub NMR Spectroscopy, and NMR Spectroscopy

Subjects
Protein Folding, [SDV]Life Sciences [q-bio], Molecular Sequence Data, Fourier Transform IR (FTIR), Biology, Biochemistry, Bacteriophage, Viral Proteins, Tube (fluid conveyance), Bacteriophages, Electron Microscopy, cardiovascular diseases, Amino Acid Sequence, Peptide sequence, Molecular Biology, [ SDV ] Life Sciences [q-bio], Tertiary Structure, Virus Assembly, Virion, Computational Biology, Nuclear magnetic resonance spectroscopy, Cell Biology, biology.organism_classification, Solid State NMR, Protein tertiary structure, In vitro, Protein Structure, Tertiary, Crystallography, Capsid, Tail Tube, cardiovascular system, Protein folding
Abstract

International audience; The majority of known bacteriophages have long tails that serve for bacterial target recognition and viral DNA delivery into the host. These structures form a tube from the viral capsid to the bacterial cell. The tube is formed primarily by a helical array of tail tube protein (TTP) subunits. In phages with a contractile tail, the TTP tube is surrounded by a sheath structure. Here, we report the first evidence that a phage TTP, gp17.1 of siphophage SPP1, self-assembles into long tubes in the absence of other viral proteins. gp17.1 does not exhibit a stable globular structure when monomeric in solution, even if it was confidently predicted to adopt the β-sandwich fold of phage λ TTP. However, Fourier transform infrared and nuclear magnetic resonance spectroscopy analyses showed that its β-sheet content increases significantly during tube assembly, suggesting that gp17.1 acquires a stable β-sandwich fold only after self-assembly. EM analyses revealed that the tube is formed by hexameric rings stacked helicoidally with the same organization and helical parameters found for the tail of SPP1 virions. These parameters were used to build a pseudo-atomic model of the TTP tube. The large loop spanning residues 40-56 is located on the inner surface of the tube, at the interface between adjacent monomers and hexamers. In line with our structural predictions, deletion of this loop hinders gp17.1 tube assembly in vitro and interferes with SPP1 tail assembly during phage particle morphogenesis in bacteria.

Published
2015
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3. Crystal Structure of Bacteriophage SPP1 Distal Tail Protein (gp19.1).

Author

Veesler, David, Robin, Gautier, Lichière, Julie, Auzat, Isabelle, Tavares, Paulo, Bron, Patrick, Campanacci, Valérie, and Cambillau, Christian

Subjects
*BACTERIOPHAGES, *BACILLUS subtilis, *ELECTRON microscopy, *X-ray crystallography, *GRAM-positive bacteria
Abstract

Siphophage SPP1 infects the Gram-positive bacterium Bacillus subtilis using its long non-contractile tail and tail-tip. Electron microscopy (EM) previously allowed a low resolution assignment of most orf products belonging to these regions. We report here the structure of the SPP1 distal tail protein (Dit, gp19.1). The combination of x-ray crystallography, EM, and light scattering established that Dit is a back-to-back dimer of hexamers. However, Dit fitting in the virion EM maps was only possible with a hexamer located between the tail-tube and the tail-tip. Structure comparison revealed high similarity between Dit and a central component of lactophage baseplates. Sequence similarity search expanded its relatedness to several phage proteins, suggesting that Dit is a docking platform for the tail adsorption apparatus in Siphoviridae infecting Gram-positive bacteria and that its architecture is a paradigm for these hub proteins. Dit structural similarity extends also to non-contractile and contractile phage tail proteins (gpVN and XkdM) as well as to components of the bacterial type 6 secretion system, supporting an evolutionary connection between all these devices. [ABSTRACT FROM AUTHOR]

Published
2010
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