Structure, function, and targets of the transcriptional regulator SvtR from the hyperthermophilic archaeal virus SIRV1.
We have characterized the structure and the function of the 6.6-kDa protein SvtR (formerly called gp08) from the rod-shaped virus SIRV1, which infects the hyperthermophilic archaeon Sulfolobus islandicus that thrives at 85 degrees C in hot acidic springs. The protein forms a dimer in solution. The NMR solution structure of the protein consists of a ribbon-helix-helix (RHH) fold between residues 13 and 56 and a disordered N-terminal region (residues 1-12). The structure is very similar to that of bacterial RHH proteins despite the low sequence similarity. We demonstrated that the protein binds DNA and uses its beta-sheet face for the interaction like bacterial RHH proteins. To detect all the binding sites on the 32.3-kb SIRV1 linear genome, we designed and performed a global genome-wide search of targets based on a simplified electrophoretic mobility shift assay. Four targets were recognized by the protein. The strongest binding was observed with the promoter of the gene coding for a virion structural protein. When assayed in a host reconstituted in vitro transcription system, the protein SvtR (Sulfolobus virus transcription regulator) repressed transcription from the latter promoter, as well as from the promoter of its own gene.
Guillière
Florence
F
Institut Pasteur, Unité de RMN des Biomolécules, CNRS URA 2185, 75015 Paris.
Peixeiro
Nuno
N
Institut Pasteur, Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, 75015 Paris.
Kessler
Alexandra
A
Institut Pasteur, Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, 75015 Paris.
Raynal
Bertrand
B
Institut Pasteur, Plate-forme de Biophysique des Macromolécules et de leurs Interactions, 75015 Paris.
Desnoues
Nicole
N
Institut Pasteur, Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, 75015 Paris.
Keller
Jenny
J
Institut de Biochimie et de Biophysique Moléculaire et Cellulaire, CNRS-UMR 8619, Université Paris 11, IFR115, Bâtiment 430, 91405 Orsay.
Delepierre
Muriel
M
Institut Pasteur, Unité de RMN des Biomolécules, CNRS URA 2185, 75015 Paris.
Prangishvili
David
D
Institut Pasteur, Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, 75015 Paris.
Sezonov
Guennadi
G
Institut Pasteur, Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, 75015 Paris; Université Pierre et Marie Curie, 4 place Jussieu, 75005 Paris, France.
Guijarro
J Iñaki
JI
Institut Pasteur, Unité de RMN des Biomolécules, CNRS URA 2185, 75015 Paris.
D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D019281:Dimerization; D015967:Gene Expression Regulation, Viral; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017433:Protein Structure, Secondary; D023642:Rudiviridae / Q000378:metabolism*; D013329:Structure-Activity Relationship; D016944:Sulfolobus / Q000821:virology*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000737:chemistry*
D014764:Viral Proteins