CotB and CotG are abundant components of the Bacillus subtilis spore coat, both possessing a series of serine‐/lysine‐rich repeats (SKR). CotG interacts with CotB promoting its polyphosphorylation in the SKR region by the CotH kinase. CotG, itself phosphorylated by CotH, is a key determinant of the striated pattern of the outer coat. Conservancy of the cotB /cotH /cotG cluster suggests that protein phosphorylation is an important mechanism in the morphogenesis of the spore surface across species.

During Bacillus subtilis endosporulation, the mother cell membrane engulfs the forespore and channel complexes form that may impact ATP concentrations in the compartments. Upon engulfment completion, channel destruction occurs and the Pro‐σ^K cleavage complex is activated. The mother cell ATP concentration was found to increase twofold coincident with channel protein loss, but this was not required to activate Pro‐σ^K cleavage.