Table 2.

TetRC58 controls expression oftetA C58 and tetR C58

StraintetRC58sourceβ-Galactosidase activitya(tetAC58::lacZ)β-Glucuronidase activitya(tetRC58::uidA)
No araWith araNo araWith ara
NT1TcR1(pZLOP1, pDLB4)None77855345
NT1TcR1(pZLOP1, pDLB4-tetR)pDLB4-tetR652186
NT1(pZLOP1, pDLB4)Chromosome19141420
NT1(pZLOP1, pDLB4-tetR)Chromosome/pDLB4-tetR252147
DH5α(pZLOP1, pDLB4)None2,2132,243NTb NT
DH5α(pZLOP1, pDLB4-tetR)pDLB4-tetR1,67829NTNT
  • a β-Galactosidase and β-glucuronidase activities are expressed as units per 109 CFU as described in Materials and Methods. Activities were determined in cultures with or without 0.4% arabinose (ara) added as an inducer.

  • b NT, not tested (E. coliDH5α has an endogenous β-glucuronidase activity).