Table 1

Incompatibility exerted by parC1 and parC2

Second plasmidR1 test plasmid
pRBJ200 (par)pGE103 (par1)pGE2 (par2)pGE3 (par12)
pBR322 (vector)1.9  × 10−2 (≡1)7.7  × 10−4 (≡1)1.4  × 10−4 (≡1)8.9  × 10−5 (≡1)
pGE303 (parC1)2.1  × 10−2 (1)3.9  × 10−3 (5)1.9  × 10−2 (130)9.2  × 10−3 (100)
pGE304 (parC2)2.0  × 10−2 (1)7.5  × 10−4 (1)1.5  × 10−2 (110)6.7  × 10−4 (8)
  • Numbers are LF values of the R1 test plasmids in the presence of the second plasmids pGE303 (parC1) or pGE304 (parC2) and are in all cases averages of three independent experiments. Numbers in parentheses are folds of destabilization (changes in LF values relative to the effect of pBR322) caused by the second plasmid (pBR322 derivatives). The effect of the pBR322 vector was set to 1. Cells of MC1000 were grown at 30°C in LB medium containing 10 μg/ml of tetracycline, thus selecting for the second plasmid (pBR322 derivatives). The plasmid vector used to construct the test plasmids was in all cases pRBJ200. Coordinates of the parC fragments are given in the text.