Figure 7.
Model for a role of YycFG in coordinating cell division with cell wall homeostasis. The present data is consistent with a model in which YycG is activated upon localization to the septum in dividing cells. This activation increases the YycF∼PO4 levels and subsequently leads to enhanced expression of genes involved in cell wall remodeling (yocH, lytE, cwlO and ydjM) and cell division (ftsA and ftsZ) and repression of genes involved in inhibiting cell wall remodeling (yoeB and yjeA). In the absence of septa in non-dividing cells YycG fails to localize, adopts a state of low activity and hence the cellular YycF pool remains unphosphorylated. Under these conditions cell wall remodeling is not required and the expression balance is tipped towards the genes involved in autolysin inhibitory processes. The precise role of the involved genes of the YycF regulon, where known, has been addressed in (Bisicchia et al., 2007).