TABLE 2.

Expression of ylmA-lacZ fusionsa

StrainRelevant genotypebFusion genotypeAddition to medium (no. of aa)β-Galactosidase activity
MU%c
BB2718Wild typeylmAp+None7.535
132.813
160.220.9
BB2724codYNone20.294
1621.6100
BB2729Wild typeylmAp1None0.04<0.2d
130.04<0.2
160.03<0.2
BB2733codY1617.7100
BB2730Wild typeylmAp2None25.290
1320.975
169.835
BB2734codY1627.9100
  • a Cells were grown in TSS glucose-ammonium medium with or without a mixture of 13 aa or 13 aa and ILV (16 aa) (see Materials and Methods). β-Galactosidase activity was assayed and expressed in Miller units (MU). All values are averages of at least two experiments, and the mean errors did not exceed 30%.

  • b All strains contained a lacA null mutation that eliminated endogenous β-galactosidase activity (9).

  • c β-Galactosidase activity of each fusion in the 16-aa-containing medium in a strain containing a codY null mutation was normalized to 100%.

  • d β-Galactosidase activity was similar to the background activity in a strain without a lacZ fusion.