Fig. 4: A revised flip state model.
(a) Non-cooperative binding model with a reversible conformational flip at each subunit following ligand binding (L). Grey box indicates alternative binding patterns. (b) Optimized transitions rates of a HCN1SM and HCN2SM. Errors are s.e.m. (c) Binding curve of HCN1SM and HCN2SM at various fcAMP concentrations overlaid with predictions from a (mean ± s.d.). Number of molecules for each fcAMP concentration is provided in Supplementary Table 1. (d) Hypothesized scheme wherein each subunit independently converts between unbound (U), bound (B), and flipped (B*) states.
