Molecules

E(b)

E b

F(b)

F b

B(e~0~1,b,Y~U~P)

B e 0 1 b Y U P

Species

E(b)

E b

F(b)

F b

B(e~0,b,Y~U)

B e 0 b Y U

Observables

Biosensor in State 1

B(e~0,b,Y~P)

B e 0 b Y P

B(e~0,b,Y~U)

B e 0 b Y U

B(e~1,b))

B e 1 b Y U P
Biosensor in State 2

B(e~0,b!1,Y~P!1)

B e 0 1b Y 1P
Biosensor in State 3 ( combination of a l l states below , see manuscript fordetails )Sequestered signaling protein

E(b!+)

E b

Reaction Rules

Phosphorylation by E.

E(b) + B(e~0,b,Y~U) <-> E(b!1).B(e~1,b,Y~U!1)

E 1 ⬆⬇b B e 0 1 take all branches, once each, in any order⬇⬇ b Y 1 ⬆⬇U

E(b!1).B(e~1,b,Y~U!1) -> E(b) + B(e~0,b,Y~P)

E 1 ⬆b B e 0 1 take one or more branches, once each, in any order⬆⬆ b Y 1 ⬆U P take all branches, once each, in any order⬇⬇
Dephosphorylation by F.

F(b) + B(e~0,b,Y~P) <-> F(b!1).B(e~1,b,Y~P!1)

F 1 ⬆⬇b B e 0 1 take all branches, once each, in any order⬇⬇ b Y 1 ⬆⬇P

F(b!1).B(e~1,b,Y~P!1) -> F(b) + B(e~0,b,Y~U)

F 1 ⬆b B e 0 1 take one or more branches, once each, in any order⬆⬆ b Y U 1 ⬆P take one or more branches, once each, in any order⬆⬆
Intramolecular reaction

B(e~0,b,Y~P) <-> B(e~0,b!1,Y~P!1)

B e 0 1 ⬆⬇b Y 1 ⬆⬇P
Intermolecular reaction

B(e~0,Y~P) + B(e~0,b) <-> B(e~0,Y~P!1).B(e~0,b!1)

B e 0 b Y 1 ⬆⬇P B e 0 1 ⬆⬇b Y U P