FIGURE 8.

Schemes for CO and Met-95 binding with monomeric EcDosH (A), dimeric EcDosH (B), and full-length EcDos (C) containing the heme domain in tandem with the phosphodiesterase domain (PDE). The rate constants were deduced from CO flash photolysis experiments from the microsecond-to-second time scales. The different Met-95 positions depict two allosteric states. For simplicity, the geminate CO rebinding phases and the picosecond Met-95 binding phases are not included in the scheme nor are the intradimer interactions between mixed CO-liganded and nonliganded heme domains.