Combined SAXS/EM Based Models of the S. elongatus Post-Translational Circadian Oscillator and its Interactions with the Output His-Kinase SasA
2011

Models of the Circadian Clock in Cyanobacteria

publication 10 minutes Evidence: high

Author Information

Author(s): Pattanayek Rekha, Williams Dewight R., Rossi Gian, Weigand Steven, Mori Tetsuya, Johnson Carl H., Stewart Phoebe L., Egli Martin

Primary Institution: Vanderbilt University

Hypothesis

How do the interactions between the proteins KaiA, KaiB, and KaiC contribute to the functioning of the circadian clock in cyanobacteria?

Conclusion

The study provides a detailed structural model of the interactions between the Kai proteins, revealing how they regulate the circadian clock in cyanobacteria.

Supporting Evidence

  • The circadian clock in cyanobacteria can be reconstituted in vitro from three proteins.
  • Models of the KaiAC and KaiBC complexes were derived from SAXS data.
  • SasA interacts with KaiC in a circadian fashion, binding more during the subjective night.
  • Binding sites for SasA and KaiB on KaiC overlap, indicating competition for binding.
  • Phosphorylation states of KaiC influence its interactions with other proteins.
  • Structural models provide insights into the dynamics of the circadian clock mechanism.

Takeaway

Scientists studied how three proteins work together to keep time in bacteria, like a clock. They found out how these proteins talk to each other to make sure everything runs smoothly.

Methodology

The study used small angle X-ray scattering (SAXS) and electron microscopy (EM) to model the interactions of the Kai proteins.

Digital Object Identifier (DOI)

10.1371/journal.pone.0023697

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