Abstract
A suicide vector named pUK4134 was constructed to enlarge the repertoire of vectors available for allelic exchange of mutated sequences in gram-negative bacteria. This plasmid combines the properties of two previously described plasmid vectors, pJM703.1 and pRTP1. pUK4134 is a suicide vector, carrying the origin of replication of the plasmid R6K and thus requiring the product of the
pir gene for its stable maintenance. The
rpsL gene encoding
Escherichia coli ribosomal protein S12 confers streptomycin sensitivity on streptomycin-resistant strains and provides a positive selection for bacteria that have lost the plasmid following allelic exchange. The
bla gene provides for selection by Ap
r. Other features are a unique
Eco RV cloning site,
oriT of plasmid RK2, and the bacteriophage λ
cos sequence. This vector was successfully used several times to carry out allelic exchange in
Yersinia pestis.
