Skip to main content
eScholarship
Open Access Publications from the University of California

Structural basis of the day-night transition in a bacterial circadian clock.

  • Author(s): Tseng, Roger
  • Goularte, Nicolette F
  • Chavan, Archana
  • Luu, Jansen
  • Cohen, Susan E
  • Chang, Yong-Gang
  • Heisler, Joel
  • Li, Sheng
  • Michael, Alicia K
  • Tripathi, Sarvind
  • Golden, Susan S
  • LiWang, Andy
  • Partch, Carrie L
  • et al.
Abstract

Circadian clocks are ubiquitous timing systems that induce rhythms of biological activities in synchrony with night and day. In cyanobacteria, timing is generated by a posttranslational clock consisting of KaiA, KaiB, and KaiC proteins and a set of output signaling proteins, SasA and CikA, which transduce this rhythm to control gene expression. Here, we describe crystal and nuclear magnetic resonance structures of KaiB-KaiC,KaiA-KaiB-KaiC, and CikA-KaiB complexes. They reveal how the metamorphic properties of KaiB, a protein that adopts two distinct folds, and the post-adenosine triphosphate hydrolysis state of KaiC create a hub around which nighttime signaling events revolve, including inactivation of KaiA and reciprocal regulation of the mutually antagonistic signaling proteins, SasA and CikA.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
Current View