Table 2.

Effect of rpoA copy number on wild-type expression of virBp::lacZ in E. coli DH5α

DH5α + plasmid:U of β-galactosidase activity ina:
IM plus glucoseIM plus glycerolIM plus glycerol plus glucose
−AS+AS−AS+AS−AS+AS
pSL2041.32.30.24.50.60.7
pSL204 and pHO981.42.61.220.8NDND
pSL204 and pPS1.31.97.23.1136.51.57.3
pSL204 and pPS1.3R2.51.71.43.0NDND
  • a Cultures were grown for 18 h in induction medium (IM) at pH 6.0 containing 55 mM glucose or glycerol or both, with (+) or without (−) 200 μM acetosyringone (AS) as indicated. Values are averages from three replicates and are expressed as units of β-galactosidase activity. ND, not determined.