Structural and funcional characterization of the sulfate ABC transporter from Xanthomonas axonopodis pv. citri and related enzymes

Abstract

This project aims to characterize functionally and structurally the pathway of sulfate assimilation in Xanthomonas citri, the causal agent of citrus canker, with emphasis on the ABC transporter involved in the uptake of this ion and enzymes responsible for the oxide/ reduction to sulfide. The research is based on two main steps aimed at, first, for the characterization of proteins involved in the pathway of assimilation (ABC transporter) and oxidereduction of the inorganic sulphate (enzymes Cys), to elucidate their structural and functional characteristics highlighting the interactions with proteins and ligands involved in the transport and / or ion metabolism. Secondly, we study specifically the activation of this pathway in different culture conditions in vitro and in vivo during infection in the plant. The activation of sbpcysWUA operon, which encodes the sulfate ABC transporter in X. citri, and expression of the proteins CysD, CysNC, CysG, CysI, and CysH CYSJ will be studied by expression of green fluorescent protein gene (eGFP) controlled by the promoter region of the operon by means of RT-PCR techniques and proteomics. Expect that the results obtained in this study represent an important contribution on the physiology and genetics of X. citri and increase knowledge about the role of sulfate in behavior in vitro and in vivo of this important pathogen. (AU)