Physical analysis of PB2, a temperate bacteriophage of Agrobacterium tumefaciens.

We have constructed a detailed physical map of PB2, a temperate bacteriophage of Agrobacterium tumefaciens. The restriction endonucleases Bam HI (3 sites), Eco RI (22 sites), Hind III (19 sites), Hpa I (5 sites), Xba I (1 site), and Xho I (1 site) were used to elucidate the map of infectious PB2 DNA. The map was generated by reciprocal sequential digestions and analysis of partial digestion products of isolated restriction fragments. We have determined the genome size as 66.35 +/- 1.71 kb. The potential of PB2 as a phage-based shuttle vector for the A. tumefaciens-plant transformation system is discussed.