The ATP-mediated regulation of KaiB-KaiC interaction in the cyanobacterial circadian clock.

The cyanobacterial circadian clock oscillator is composed of three clock proteins--KaiA, KaiB, and KaiC, and interactions among the three Kai proteins generate clock oscillation in vitro. However, the regulation of these interactions remains to be solved. Here, we demonstrated that ATP regulates formation of the KaiB-KaiC complex.