Transcriptional regulators in hyperthermophiles archea and their virus : molecular, fonctional and genetic analysis
type: Dataset
description: In Archaea cells all information processes, including transcription, are performed by the Eukarya-like proteins. While the transcriptional machinery of archaea has been well characterized structurally and functionally, very few information concerning the regulation of its activity is available. By working with both cell (crenarchaeota Sulfolobus islandicus) and viral models, we have performed an in-depth study of three transcriptional regulators: two viral regulators, SvtR and AFV1p06, and a cell regulator Sta1. The obtained results allow to better understand the mechanisms of transcriptional regulation in archaea. Concerning the protein SvtR encoded by the virus SIRV1 that infects S. islandicus, we continued the research project that had identified its structure and function. We were focused on identification and characterization of all of SvtR targets in the viral genome and on the study of the mechanisms of regulation. For this purpose, we established the sequence of consensus site recognized by SvtR using systematic mutagenesis of one of its previously characterized binding sites. This site is present in the promoters of 10 genes meaning that SvtR may regulate the activity of more than 20% of SIRV1 genes. Its targets include all known genes encoding proteins of the viral capsid. Functional analysis of SvtR has demonstrated that, according to the target, this protein is a versatile regulator acting as transcriptional activator or repressor. Taking as a model the gp30 gene promoter, we demonstrated by several approaches that regulation of this promoter includes the polymerization of the protein from its primary binding site towards the TATA-box. Such a mechanism of transcriptional regulation is new in archaea. Second, we performed a structural analysis of the protein AFV1p06 encoded by the virus AFV1 which infects Acidianus hospitalis. The structural analysis of AFV1p06 revealed the presence of a C2H2 zinc finger domain regarded hitherto as specific to eukaryotes.…
identifier: NNT: 2014PA066010
issued: 2026-05-05T20:22:17.872793
language: fr
modified: 2026-05-05T20:22:17.872797
contact point: Organization
  fn: CCSD
keyword: archaea-cells
keyword: archees
keyword: infoeu-reposemanticsdoctoralthesis
keyword: regulation-transcriptionnelle
keyword: sdvbbmbmlife-sciences-q-biobiochemistry-molecular-biologymolecular-biology
keyword: sirv
keyword: sulfolobales
keyword: sulfolobus
keyword: theses
keyword: transcription
keyword: transcriptional-machinery
keyword: virus-darchees
landing page: https://theses.hal.science/tel-00966549

Transcriptional regulators in hyperthermophiles archea and their virus : molecular, fonctional and genetic analysis
type: Distribution
format: HTML
issued: 2026-05-05T20:22:17.907509
modified: 2026-05-05T20:22:17.845592
access URL: https://theses.hal.science/tel-00966549

test_moissonnage_selune
type: Agent