Analysis of a 1600-kilobase Rhizobium meliloti megaplasmid using defined deletions generated in vivo.

A series of 120-600 kilobase deletions with defined endpoints were made in the 1600-kilobase Rhizobium meliloti megaplasmid pRmeSU47b, by homologous recombination between the IS50 elements of transposon insertions. Utilizing IS 50-mediated homologous recombination we also made defined reductions in deletion size and combined adjacent deletions. Deletion structure was confirmed by phage transduction and Southern hybridization analysis. …