Has an extremely high oxygen affinity. In a vacuum, it takes several minutes to release its oxygen compared to milliseconds for a normal globin. Could be used as an oxygen scavenger for sterol biosynthesis. Homooctamer. Consists of two tandemly linked globin-like sequences which each bind a heme group and a C-terminal extension which may act as a cement between the eight subunits. Belongs to the globin family.