Binding Leverage as a Molecular Basis for Allosteric Regulation
(A) Binding analysis of CAP based on PDB entry 1g6n. The coloring is based on fi(0.1). To help the eye the most important sites have been marked with circles. The dimer is symmetric; the sites hidden in this view have similar properties to the ones shown. The location of the cAMP ligand in the crystal structure is marked by black spheres. (B) Putative free energy landscape at an intermediate cAMP concentration. The x-axis indicates the number of cAMP molecules bound, and the y-axis conformational degrees of freedom. We indicate that the conformational entropy is highest when one cAMP is bound by the wider minimum.