The pathogen-host cross-talking usually involved in different virulence factors, which play crucial roles in the pathogen virulence regulation. Here in our work, we determined crystal structures of three novel virulence factors BswR, SghA, and SghR as well as relevant complex structures. BswR mediates bacterial motilities and biofilm formation, regulates small RNA rsmZ transcription, the molecular basis for the regulation will be proposed. SghA and SghR were identified and characterized to regulate the Agrobacterium infection of plant hosts. SghR is a repressor of SghA, and negatively regulates SghA expression until the environmental signal presence. Detailed structural and functional analyses of SghA-SghR in the regulation of agrobacterial tumorigenesis and the allosteric mechanism of SghR in the regulation of SghA will be presented.Doctor of Philosophy (SBS
