Iron uptake and levan biosynthesis in Erwinia spp.

Erwinia amylovora is the etiological agent of fire blight, a devastating disease, which is a global threat to commercial apple and pear production. The Erwinia genus includes a wide range of different species belonging to plant pathogens, epiphytes and even opportunistic human pathogens. Aim of the thesis was to investigate enzymes that are relevant for the pathogenicity of Erwinia amylovora. With a comparative genomic analysis within Erwinia genus, the gene-pathogenicity and gene–host relationships have been analyzed, as well as the taxonomic relations within phytopathogen e non-phytopathogen Erwinia strains. The proteins responsible for the siderophore biosynthesis and iron uptake were mainly investigated using X-ray crystallography. Their structures provide the basis for a rational and structure based development of inhibitory compounds against E amylovora. Furthermore, the enzyme deputy to levan biosynthesis from the epyphite Erwinia tasmaniensis has been studied structurally and biochemically, with the aim of understanding the differences versus the enzyme from E. amylovora. The results of this work advance our understanding of the molecular mechanisms of the causative agent of fire blight, E. amylovora. This work provides relevant information about the bacterium and its genus, which enrich the scientific community and increase the knowledge about this pathogen.