A phagemid shuttle vector based on filamentous phage φLf and theE. coli vector pOK12 for use inXanthomonas campestris

AnE. coli-Xanthomonas shuttle vector, p2GP (3.3 kb), was constructed by fusing pOK12 with a DNA fragment carrying gene II andori from filamentous phage φLf. p2GP retains the advantages afforded by pOK12 and can replicate in differentX. campestris pathovars. Superinfection ofX. c. pv.campestris cells harboring p2GP or its derivatives with φLf causes the release of ssDNA-containing recombinant phage particles which are sources of single-stranded template for sequencing the inserts.