Fig. 5.
Influence of activation energy difference and the KaiA abundance on the temperature dependence of the period. (A) Diagram of the temperature dependence of the cycle against activation energy ratio (Edp/Ep) and abundance of total KaiA (Atotal). Red: temperature-compensated oscillation with ∂τ/∂β ∼ 0 (τ: the period) below the critical temperature. Green: oscillation showing transition at the critical temperature. Blue: oscillation without transition, with a simple increase with temperature following the Arrhenius form. Black: no oscillations at all. Orange dotted line: transition line theoretically estimated from the condition at which the speeds of phosphorylation and dephosphorylation are equal. As Edp/Ep increases from 0 to 1, we successively see temperature compensation, transition, and disappearance of oscillation. (For the case with Ep < Edp, see SI Appendix.) As Atotal increases, the width of the temperature compensation region decreases. (B) Effect of KaiA increase on the period. An increase in KaiA leads to narrowing of the range of the periodic solution and also the range of temperatures at which temperature compensation occurs.