How a cyanobacterium tells time.
The cyanobacterium Synechococcus elongatus builds a circadian clock on an oscillator composed of three proteins, KaiA, KaiB, and KaiC, which can recapitulate a circadian rhythm of KaiC phosphorylation in vitro. The molecular structures of all three proteins are known, and the phosphorylation steps of KaiC, the interaction dynamics among the three Kai proteins, and a weak ATPase activity of KaiC have all been characterized. An input pathway of redox-sensitive proteins uses photosynthetic function to relay light/dark information to the oscillator, and signal transduction proteins of well-known families broadcast temporal information to the genome, where global changes in transcription and a compaction of the chromosome are clock regulated.
Dong
Guogang
G
Center for Biological Clocks Research and Department of Biology, Texas A&M University, College Station, TX 77843-3258, United States.
Golden
Susan S
SS
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D002940:Circadian Rhythm; D056925:Circadian Rhythm Signaling Peptides and Proteins; D003624:Darkness; D015964:Gene Expression Regulation, Bacterial; D008027:Light; D046940:Synechococcus / Q000502:physiology*
D001426:Bacterial Proteins; D056925:Circadian Rhythm Signaling Peptides and Proteins; C114269:KaiA protein, cyanobacteria; C114270:KaiB protein, cyanobacteria; C114271:KaiC protein, cyanobacteria