Figure 1

The sporulation initiation network in B. subtilis . The histidine kinase KinA responds to the environmental conditions (SS) and to artificial induction (IPTG) by auto-phosphorylation and pass phosphoryl groups to an intermediate response regulator, Spo0F. Subsequently, the phosphotransferase Spo0B, transfers it to the transcription factor, Spo0A. Spo0A~P activates the genes that govern forespore and mother cell specific transcription factors and exerts a positive feedback on phosphorelay components through the repression of abr B gene expression.