Agrobacterium tumefaciens
The conjugation machinery of some bacteria (and archaeal flagella) is capable of transporting both DNA and proteins. It was discovered in "Agrobacterium tumefaciens", which uses this system to introduce the Ti plasmid and proteins into the host, which develops the crown gall (tumor). The VirB complex of "Agrobacterium tumefaciens" is the prototypic system.