title: Characterization of the LysR-type transcriptional regulator YcjZ-like from Xylella fastidiosa overexpressed in Escherichia coli.
abstract: The Xylella fastidiosa 9a5c strain is a xylem-limited phytopathogen that is the causal agent of citrus variegated chlorosis (CVC). This bacterium is able to form a biofilm and occlude the xylem vessels of susceptible plants, which leads to significant agricultural and economic losses. Biofilms are associated with bacterial pathogenicity because they are very resistant to antibiotics and other metal-based chemicals that are used in agriculture. The X. fastidiosa YcjZ-like (XfYcjZ-like) protein belongs to the LysR-type transcriptional regulator (LTTR) family and is involved in various cellular functions that range from quorum sensing to bacterial survival. In the present study, we report the cloning, expression and purification of XfYcjZ-like, which was overexpressed in Escherichia coli. The secondary folding of the recombinant and purified protein was assessed by circular dichroism, which revealed that XfYcjZ-like contains a typical α/β fold. An initial hydrodynamic characterization showed that XfYcjZ-like is a globular tetramer in solution. In addition, using a polyclonal antibody against XfYcjZ-like, we assessed the expression profile of this protein during the different developmental phases of X. fastidiosa in in vitro cultivated biofilm cells and demonstrated that XfYcjZ-like is upregulated in planktonic cells in response to a copper shock treatment. Finally, the ability of XfYcjZ-like to interact with its own predicted promoter was confirmed in vitro, which is a typical feature of LysR. Taken together, our findings indicated that the XfYcjZ-like protein is involved in both the organization of the architecture and the maturation of the bacterial biofilm and that it is responsive to oxidative stress.
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: André S
authors.initials: AS
authors.lastname: Santiago
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Clelton A
authors.initials: CA
authors.lastname: Santos
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Juliano S
authors.initials: JS
authors.lastname: Mendes
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Marcelo A S
authors.initials: MA
authors.lastname: Toledo
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Lilian L
authors.initials: LL
authors.lastname: Beloti
authors.affiliation: Centro APTA Citros Sylvio Moreira/IAC, Rodovia Anhanguera Km 158, Cordeirópolis, SP, Brazil.
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: Souza
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade Estadual de Campinas, Campinas, SP, Brazil; Departamento de Biologia Vegetal, Instituto de Biologia (IB), Universidade Estadual de Campinas, Campinas, SP, Brazil. Electronic address: anete@unicamp.br.
authors.forename: Anete P
authors.initials: AP
authors.lastname: Souza
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects; D003300:Copper / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000187:drug effects; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D044167:Xylella / Q000187:drug effects / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D003300:Copper
keywords: Biofilm; Transcriptional regulator; Xylella fastidiosa; YcjZ