5.4.4.5	heme	PpoA contains a high spin ferriheme. PpoA uses different heme domains to catalyze two separate reactions. Within the heme peroxidase domain, linoleic acid is oxidized to (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate by abstracting a H-atom from C-8 of the fatty acid, yielding a carbon-centered radical that reacts with molecular dioxygen. In the second reaction step, (8R,9Z,12Z)-8-hydroperoxy-9,12-octadecadienoate is isomerized within the P450 heme thiolate domain to (5S,8R,9Z,12Z)-5,8-dihydroxy-9,12-octadecadienoate	704466