FIGURE 3.

Three-dimensional structures of alkane hydroxylase enzymes. (A) The crystal structure of particulate methane monooxygenase (pMMO) from Methylococcus capsulatus (Lieberman and Rosenzweig, 2005). The structure is shown in cartoon representation and colored by chain; the Zn and Cu ions are shown as spheres. (B) The crystal structure of soluble methane monooxygenase (sMMO) from Methylococcus capsulatus (Rosenzweig and Lippard, 1994). The structure is shown in cartoon representation and colored by chain; the di-iron centers are shown as spheres. (C) The crystal structure of P450cam from Pseudomonas putida (Poulos et al., 1987). The structure is shown in cartoon representation, with the heme shown in stick representation and the iron shown as a sphere. Camphor is also shown in stick representation and colored magenta. (D) The crystal structure of P450 BM-3 from Bacillus megaterium (Ravichandran et al., 1993). The structure is shown in cartoon representation, with the heme shown in stick representation and the iron shown as a sphere.