A Tn4001 delivery system for Streptococcus gordonii (Challis).

The Staphylococcus aureus transposon Tn4001 was found to transpose in Streptococcus gordonii. Transposition sites appeared to be randomly distributed, and the element was stable in the absence of antibiotic selection. An increase in transposition frequency was noted when the delivery plasmid was propagated in a Dam- Dcm- Escherichia coli host strain. The utility of Tn4001 was demonstrated by the generation of lactose-negative mutants. Small size, clonal stability, random transposition, and known nucleotide sequence make Tn4001 a useful addition to the repertoire of tools available to the streptococcal geneticist.