From phenomenon to mechanism in the circadian clock of Synechococcus elongatus

Creative and collaborative research in the early 21st century revealed the mechanistic secrets of the cyanobacterial circadian clock, a nanomachine whose function can be studied in vitro. The structural dynamics of the Synechococcus elongatus circadian oscillator, comprising KaiA, KaiB, and KaiC, establish a near 24 h cycle of activity of the global transcription regulator RpaA by rhythmically changing the interaction platform of kinases that control RpaA phosphorylation.