FUNCTIONAL FEATURES OF ORIV OF THE BROAD-HOST-RANGE PLASMID-RSF1010 IN PSEUDOMONAS-AERUGINOSA

The broad host range plasmid RSF1010 requires for its replication in E scherichia coli three plasmid-encoded proteins and specific nucleotide sequences ssiA, ssiB, and iterons in the oriV(RSF1010). In Pseudomona s aeruginosa, a recombinant mini-RSF1010 plasmid lacking ssiB lost its replication ability, but a miniplasmid lacking ssiA or carrying a pri mosome assembly site in place of ssiA could replicate. Moreover, ssiA, as a sole ssi signal, in the orientation that ssiB had originally tak en was sufficient for replication of the miniplasmid. These results in dicated that only one RSF1010-specific ssi signal in the orientation t hat ssiB takes in wild-type oriV(RSF1010) was essential for replicatio n of RSF1010. Replication of the miniplasmids was dependent on the thr ee plasmid-encoded proteins, RepA, B', and C, as in E. coli. (C) 1994 Academic Press, Inc.