Type IV secretion system, VirB3 / TrbD / AvhB (IPR007792)

Short name: T4SS_VirB3/TrbD/AvhB

Overlapping homologous superfamilies


Family relationships


This entry represents type IV secretion system proteins VirB3, TrbD and AvhB. Type IV secretion systems are found in plant and animal pathogens, as well as in symbiotic bacteria. The tumour-inducing (Ti) plasmid of Rhizobium radiobacter (Agrobacterium tumefaciens) encodes two DNA transfer systems: VirB and Trb, where the virB operon is required for the transfer DNA to the plant host, and the trb system is required for the conjugal transfer of the Ti plasmid between cells of Agrobacterium [PMID: 9679196, PMID: 12169609]. In addition, VirB3 is found associated with bacterial inner and outer membranes and assists T pilus formation as an assembly factor [PMID: 8405938]. The conjugal transfer protein TrbD contains a nucleotide binding motif and may provide energy for the export of DNA or the export of other Trb proteins [PMID: 8763954]. This entry also includes avhB (Agrobacterium virulence homologue virB), which is most similar to the VirB type IV secretion system of Bartonella henselae (Rochalimaea henselae) [PMID: 12169609].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.