Estudos de relação estrutura-função de proteinas da bacteria Xylella fastidiosa envolvidas em patogenicidade e adaptação

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The two-component regulatory system are signal transduction strategies used by bacteria in order to sense the surrounding the environment. This system is composed by two proteins, a transmembranic sensor protein (PhoQ) that interacts with the other one, a response regulator protein (PhoP) that once it has been phosphorilated, it generates a response by regulating the expression of several genes, involved in virulence and adaptation. In Xy/ella fastidiosa this system is formed, at least, by these two genes: Xf0389 (PhoP) and Xf0390 (PhoQ). The Xf0390 was cloned only in pGEM-T-Easy, while the Xf0389 was ais o cloned into the expression vector pET28a(+) and the protein was expressed in E. colí C43 (DE3) strain. Circular dichroism spectra of the purified protein show a high content in alpha-helix. A three-dimensional model of Xf0389 was built and the modeling was based on the protein DNA binding response regulator D (DrrD) from Thermotoga maritima (PDB accession code: 1 kgs). Typically, response regulators have two domains: a N-terminal regulatory domain which is phosphorilated and a C-terminal effector domain which has a DNA binding motif. Based on the sequence of the effector domain, there are three subfamilies: NtrC, NarUFixJ and OmpRlPhpB. Xf0389 has characteristics of the proteins belonging to the OmpRlPhoB subfamily

ASSUNTO(S)

proteinas-estrutura

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