Table 3.

TetRC58 and TetRRP4 recognize noncognate tet operators

Strainβ-Galactosidase activityaGrowth on TC mediumb
No TCWith TCNo araWith ara
DH5α(pRK415K, pBetR)NTc NT++
DH5α(pRK415K, pBAD22)NTNT++++
DH5α(pZLOP1, pRK415K)3872,154NTNT
  • a β-Galactosidase activity is expressed as units per 109 CFU as described in Materials and Methods. When needed, tetracycline (TC) was added to the culture at 10 μg/ml as an inducer.

  • b Growth was assessed on LB medium supplemented with tetracycline at 5 and 10 μg/ml (TC medium) and with or without 0.4% arabinose (ara) added as an inducer. ++, good growth; −, no growth.

  • c NT, not tested.