Fig. 2: Common structure of proofreading and sensing models.
a Murugan’s generalized proofreading scheme6, where the key assumption is that there is a “discriminatory fence” dividing the states into two halves, and every transition depending on the energy difference Δ crosses this fence. We are showing just half of a symmetric kinetic scheme—restricting attention to the part of the graph on which ν depends, which is just the reactions involving bound states containing W (neglecting the totally analogous ones involving R). b The general receptor model used in ref. 21 to study the sensing of a ligand concentration has the same structure, with the separation between the bound and unbound states of the receptor playing the role of the “fence”.
