Accumulation of RpoS-lacZ in hns mutants

Strain or mutation(s)β-Galactosidase activity
Long fusionaShort fusionb
Wild type0.16 ± 0.070.89 ± 0.11
hns1.91 ± 0.111.58 ± 0.025
rssB1.02 ± 0.10ND
hns rssB1.93 ± 0.01ND
  • a Cells were grown in LB medium at 37°C, and ß-galactosidase was assayed as previously described (24). Units are arbitrary specific activity machine units about 25-fold lower than Miller units. This fusion protein is subject to RssB-dependent degradation. The strains used were strains SG30013 (wild-type, RpoS750::LacZ), SG30059 (hns::kan), SG30018 (rssB::tet), and YN534 (hns::kan rssB::tet), all derivatives of SG30013 (see Table S1 in the supplemental material).

  • b Cells were grown as described in footnote a. The fusion protein is stable. The strains used were strains EM1246 (wild-type, RpoS477::LacZ) and YN714 (hns::kan), a derivative of EM1246. ND, not determined.