Characterization of two transcriptional activators: MafR of Enterococcus faecalis and MgaP of Streptococcus pneumoniae

The Gram-positive bacteria Enterococcus faecalis and Streptococcus pneumoniae are inhabitants of the human body. Whereas E. faecalis is a usual commensal of the gastrointestinal tract, S. pneumoniae is normally found in the nasopharynx of healthy individuals. Nevertheless, their ability to adapt to...

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Detalles Bibliográficos
Autor: Moreno Blanco, Ana
Tipo de recurso: tesis doctoral
Fecha de publicación:2021
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/11564
Acceso en línea:https://hdl.handle.net/20.500.14352/11564
Access Level:acceso abierto
Palabra clave:579.86(043.2)
Transcriptional activators
MafR of Enterococcus faecalis
MgaP of Streptococcus pneumoniae
Activadores transcripcionales
MafR de Enterococcus faecalis
MgaP de Streptococcus pneumoniae
Microbiología (Biología)
2414 Microbiología
Descripción
Sumario:The Gram-positive bacteria Enterococcus faecalis and Streptococcus pneumoniae are inhabitants of the human body. Whereas E. faecalis is a usual commensal of the gastrointestinal tract, S. pneumoniae is normally found in the nasopharynx of healthy individuals. Nevertheless, their ability to adapt to diverse stress conditions allows them to invade other niches of the human host causing a variety of life-threatening infections. In general, bacterial adaptation to new niches requires the action of proteins that act as global transcriptional regulators. These proteins activate and/or repress the transcription of multiple genes in response to specific signals. The Mga/AtxA family of global transcriptional regulators includes various proteins of Gram-positive pathogenic bacteria: AtxA (Bacillus anthracis), Mga (S. pyogenes), MgaSpn (S. pneumoniae), and MafR (E. faecalis). Several studies have shown that these transcriptional regulators play a role in bacterial virulence (Fouet, 2010; Hemsley et al., 2003; McIver, 2009; Ruiz-Cruz et al., 2016). MafR from Enterococcus faecalis: Previous studies in our laboratory showed that the MafR protein of E. faecalis strain V583 (MafRV583) binds to linear DNA fragments generating multimeric complexes, and this binding has little or no sequence specificity (Ruiz-Cruz, 2015). Furthermore, using microarrays designed for strain OG1RF, it was shown that MafR activates, directly or indirectly, the transcription of at least 87 genes. Many of them are organized in operons and encode proteins involved in the utilization of carbon sources (Ruiz-Cruz et al., 2016). In this Thesis, we have worked on the following objectives: (a) Analysis of the DNA-binding properties of MafR from strain OG1RF (MafROG1RF) and (b) Identification of genes regulated directly by MafROG1RF...