Role of Agrobacterium virB Genes in Transfer of T Complexes and RSF1010

Nonpolar virB mutants of Agrobacterium tumefaciens were tested for RSF1010 mobilization and extracellular complementation. virB2 to virB11 were essential for transfer in both assays. virB1 was essential only for high frequency transfer of RSF1010 and VirE2. Coordinated transfer of a preassembled T complex is supported by these data and competition studies.