Table 3.

β-Galactosidase production in various strains showing effects of comX mutations on CSP-dependent regulation of transformation genes

StrainlacZ reporter fusion sitesPhenotypebβ-Galactosidase activitya
CloneExpt 1Expt 2Expt 3Expt 4
−CSP+CSP−CSP+CSP−CSP+CSP−CSP+CSP
CPM6 comC WT330360150150
CPM10 comC ComX1ComX2 1150300390
2240430
CP1649 comA ComA 2.21302.3130
CPM11 comA ComX1 ComX2ComA 12.01502.7210
20.9270
CPM3 comX1 WT0.91003.250
CPM16 comX2 WT13.51304.1190
23.21404.1180
CPM17 comX1 ComE 12.72.62.53.4
23.63.5
CPM9 comX2 ComX2 18.72603.21504.6170
22.4190
CPM4 comX2 ComX1ComX2 13.15703.33303.1390
22.7390
CPM7 ssb2 WT0.91302.21101.760
CPM12 ssb2 ComX1ComX2 11.82.03.33.2
23.94.5
CP1548 cglA CglA 3.43701603.5190
CPM13 cglA ComX1 ComX2CglA 11.81.82.92.9
23.93.1
CP1601 celB CelB 1.5901.82.550
CPM14 celB ComX1 ComX2CelB 12.22.12.93.2
23.54.4
CP1506 cflA CflA 0.59070
CPM15 cflA ComX1 ComX2CflA 11.63.03.2
23.74.1
CP1250NoneWT0.41.52.92.83.12.5
  • a Two independent clones of each strain were grown in CAT containing 6 mM HCl to an OD550 of 0.05 in several experiments. After 1 ml of culture was either not treated (−CSP) or treated (+CSP) with CSP and NaOH, incubation was continued for 40 min. Enzyme activity in crude cell extract at 40 min was measured by the ONPG assay and is expressed in Miller units (30).

  • b WT, wild type.