TABLE 2.

Regulation of trpP and pabA expression

FusionRelevant genotypeβ-Galactosidase activityaInhibition ratio (−Trp/+Trp)mtrB/WTb
−Trp+Trp
pabA′-′lacZWild type178 ± 1034 ± 45.216
pabA′-′lacZ mtrB 545 ± 55518 ± 381.1
pabA′-′lacZ rho 99 ± 1016 ± 36.227
pabA′-′lacZ mtrB rho 432 ± 22450 ± 131.0
trpP′-′lacZWild type201 ± 331.3 ± 0.3155923
trpP′-′lacZ mtrB 1,200 ± 1601,200 ± 2201.0
trpP′-′lacZ rho 184 ± 391.4 ± 0.4131929
trpP′-′lacZ mtrB rho 1,300 ± 2301,340 ± 1701.0
  • a β-Galactosidase activity is given in Miller units (25).

  • b The extent of TRAP-dependent inhibition was determined by dividing the value for the mtrB mutant by the value for the corresponding wild-type strain (WT) +Trp.