Consider the case of a competitive binding of an activator A and a repressor R with D and assume that before they can bind to D they have to cooperatively bind according to the following reactions:
in which the complex An contains n molecules of A and the complex Rm contains m molecules of R. The competitive binding reactions with A are given by
and Dtot = D + C + C′. What are the steady state expressions for C and D as functions of A and R?