Table 1

Expression of rocG-lacZ fusions

Strain (genotype)β-galactosidase activity in different media
Succinate GlutamateSuccinate Glutamate Ornithine
rocG-lacZ at the rocG locus
 BB1434 (wild-type)1.510.5
 BB1481 (sigL::aphA3)2.11.6
 BB1437 (rocRΔ3::aphA3)1.21.4
 BB1440 [rocR(T120I)]2.810.2
rocG-lacZ at the amyE locus
 BB1455 (wild-type)1.50.7
 BB1458 (rocD::aphA3)1.53.1
  • Strain BB1434 and its derivatives contain a rocG-lacZ fusion [as in pBB923 (Fig. 2A)] at the rocG locus of the chromosome. Strain BB1455 contains the same fusion at the ectopic (unlinked) amyE locus. Null mutations in sigL, rocR, and rocD and the constitutive rocR(T120I) mutation were as described (10, 13, 14). Endogenous β-galactosidase activity in the absence of any rocG fusion was 1-2 units and was not subtracted.