Phosphorelay

The phosphorelay is a complex variation of a two-component regulatory system. It includes phosphotransferases that transfer the phosphoryl group from the sensor kinases to the ultimate target. The sporulation initiation phosphorelay is the paradigm of this class of signal transduction systems.

The kinases

• KinA
• KinB
• KinC
• KinD
• KinE

The phosphotransferases

• Spo0F
• Spo0B

The ultimate target

• Spo0A

Phosphatases controlling the phosphorelay (and peptides that modulate their activity)

• Spo0E: dephosphorylation of Spo0A
• YisI: dephosphorylation of Spo0A
• YnzD: dephosphorylation of Spo0A
• RapA, PhrA: dephosphorylation of Spo0F
• RapB: dephosphorylation of Spo0F
• RapE, PhrE: dephosphorylation of Spo0F