TABLE 4.

Complementation analysis of the ΔoriT plasmids pUIV265 and pUIV266^a

Complementing plasmid	Mobilization frequency (SD)
Using pUIV265
pUC19 (negative control)	<10−7
pUIV201 [pUC19::150 bp (ColE1-oriT)]	5 × 10−2 (1 × 10−2)
pUIV247 (pCR-blunt::ΔIR)	5 × 10−4 (2 × 10−4)
pUS4601 (ColE1::Km, positive control)	4 × 10−2 (2 × 10−2)
Using pUIV266
pSU18 (negative control)	<10−7
pUIV245 [pSU18::89 bp (ColE1-oriT)]	2 × 10−2 (1 × 10−2)
pUIV230 [pSU18::mob(ColE1), positive control]	2 × 10−2 (1 × 10−2)

^aDerivatives of E. coli strain BL21(DE3) carrying pUIV265 and each of the plasmids shown under “using pUIV265” or pUIV266 and each of the plasmids shown under “using pUIV266” were separately used as donors in triparental matings using DH5α/R64drd-11 as the helper and HMS174 as the final recipient. After filter mating, bacteria were plated on selective media containing Rif to counterselect donors and Cm to select for pUIV265 or pUIV266 mobilization. Transfer frequencies are expressed as the number of transconjugants per recipient cell and are the average of at least three separate experiments.