Regulates multiple virulence functions including type IV pilus (T4P)-mediated assembly and twitching motility as well as cAMP-dependent virulence gene expression (PubMed:15720546). Regulates intracellular cyclic AMP (cAMP) levels through the activation of adenylate cyclase CyaB (PubMed:21264306). Functions also as a scaffold linking FimV and PilG at the pole, where type IV pilus (T4P), the Chp chemosensory system and the CyaB adenylate cyclase interact (PubMed:27145134). Interacts with PilG and FimV. Localizes to poles in a FimV-dependent manner. Mutants show increased autolysis, reduced levels of surface-assembled type IV pili, twitching motility and diminished production of type III secreted effector.