Functional features of an ssi signal of plasmid pGKV21 in Escherichia coli

The functional features of an ssi signal of plasmid pGKV21 in Escherichia coli were analyzed using an ssi signal-deleted plasmid. Results of the study revealed that ssi activity is orientation specific with respect to the direction of replication. Furthermore, the plasmid lacking an ssi signal accumulated much more plasmid single-stranded DNA as compared to the wild-type plasmid.