Table 3. Mechanisms and q parameters for N = 3.

	qij
	q0	q1	q2	q3	q10	q11	q12	q13
State	E	EH	EHH	EHHH	ES	ESH	ESHH	ESHHH
(SH3)	α3γ3	3α3γ3	3α2γ3	γ3	α3γ3	3α3γ2	3α2γ	1
(SH3)a	1	3	3	1	1	3	3	1
(SH2)H	αβγ2	2αβγ2	βγ2	0	αβγ2	2αβγ	β	1
(SH)(H2)	αβ2γ	αβ2γ	0	0	αβ2γ	αβ2	2αβ	1
(SH)HH	β1β/γ	β1β2γ	0	0	β1β2γ	β1β2	β2	1
H(SH2)	αβ2γ2	αβ2γ2	2αβγ2	γ2	0	αβ2γ2	2αβγ	1
(H2)(SH)	αβγ	2αβγ	βγ	γ	0	0	βγ	1
HH(SH)	β1β2γ	β1β2γ	β2γ	γ	0	0	β2γ	1
H(SH)H	β1β2γ	β1β2γ	β2γ	0	0	β1β2γ	β2	1
(H3)S	α3	3α3	3α2	1	0	0	0	1
(H2)HS	αβ	2αβ	β	1	0	0	0	1
H(H2)S	αβ2	αβ2	2αβ	1	0	0	0	1
HHHS	β1β2	β1β2	β2	1	0	0	0	1
(H2)SH	αβ	2αβ	β	0	0	0	β	1
HHSH	β1β2	β1β2	β2	0	0	0	β2	1
HS(H2)	αβ2	αβ2	0	0	0	αβ2	2αβ	1
HSHH	β1β2	β1β2	0	0	0	β1β2	β2	1
S(H3)	α3	0	0	0	α3	3 α3	3 α2	1
S(H2)H	αβ	0	0	0	αβ	2αβ	β	1
SH(H2)	αβ2	0	0	0	αβ2	αβ2	2αβ	1
SHHH	β1β2	0	0	0	β1β2	β1β2	β2	1

The top part shows mechanisms with random binding of the substrate and (part of) the co-ions, and the bottom part shows mechanisms with ordered binding of the substrate. Bold entries show the q parameters for co-ion binding in the response model (Online supplementary material file S3).

^aFully random with no interaction between the sites: α = 1, γ = 1.