Fig. 2. YlyA exhibits a specific effect on σG-dependent transcription.
β-galactosidase activity (arbitrary units; AU) was monitored for samples taken at the indicated time points after sporulation was induced by resuspension. (A) PsspB-directed lacZ activity was determined in wild type cells (squares), ylyA mutant cells (triangles), ylyA mutant cells carrying a copy of ylyA at the ectopic sacA locus (diamonds), and ylyA mutant cells carrying a copy of ylyA expressed from the sspB promoter at the ectopic sacA locus (circles). All strains carry the PsspB-lacZ reporter construct at the amyE locus. (B) PspoVT-directed lacZ activity was determined in wild type cells (squares), ylyA mutant cells (triangles), and ylyA mutant cells carrying a copy of ylyA expressed from the sspB promoter at the ectopic sacA locus (circles). All strains carry the PspoVT-lacZ reporter construct at the amyE locus. (C) Forespore-specific T7 RNA polymerase-directed PT7-lacZ activity was determined in wild type cells (squares), ylyA mutant cells (triangles), and ylyA mutant cells carrying a copy of ylyA expressed from the sspB promoter at the ectopic sacA locus (circles). All strains carry the construct expressing T7 RNA polymerase (PspoIIQ-T7 RNAP) at the ylnF locus, whereas the PT7-lacZ reporter gene was integrated at the ywrK locus. (D) PsspB-directed lacZ activity was determined in ylyA mutant cells carrying a copy of ylyA (circles), yocK (plus sign), yteA (minus sign) and E. coli dksA (cross) expressed from the sspB promoter at the ectopic sacA locus (circles).