Abstract
Bacteria use a variety of secretion systems to translocate macromolecules across the bacterial cell envelope. The type IV secretion system (T4SS) of the phytopathogen Xanthomonas citri is responsible for the secretion of toxins that kill other Gram-negative bacteria. The T4SS are very large molecular assemblies formed by two subcomplexes, the core complex (~ 1 MDa) and the inner membrane …